build: add check step to verify compilation

MCP fixes

.github/actions/install/action.yml

@@ -13,7 +13,7 @@ inputs:
   zig-v8:
     description: 'zig v8 version to install'
     required: false
-    default: 'v0.3.4'
+    default: 'v0.3.7'
   v8:
     description: 'v8 version to install'
     required: false

.github/workflows/nightly.yml

@@ -7,7 +7,7 @@ env:
   AWS_REGION: ${{ vars.NIGHTLY_BUILD_AWS_REGION }}
 
   RELEASE: ${{ github.ref_type == 'tag' && github.ref_name || 'nightly' }}
-  VERSION: ${{ github.ref_type == 'tag' && github.ref_name || '1.0.0-nightly' }}
+  VERSION_FLAG: ${{ github.ref_type == 'tag' && format('-Dversion_string={0}', github.ref_name) || format('-Dpre_version={0}', 'nightly') }}
 
 on:
   push:
@@ -45,7 +45,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 -Dversion_string=${{ env.VERSION }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 ${{ env.VERSION_FLAG }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -85,7 +85,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic -Dversion_string=${{ env.VERSION }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic ${{ env.VERSION_FLAG }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -127,7 +127,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dversion_string=${{ env.VERSION }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast ${{ env.VERSION_FLAG }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -167,7 +167,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dversion_string=${{ env.VERSION }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast ${{ env.VERSION_FLAG }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}

Dockerfile

@@ -3,7 +3,7 @@ FROM debian:stable-slim
 ARG MINISIG=0.12
 ARG ZIG_MINISIG=RWSGOq2NVecA2UPNdBUZykf1CCb147pkmdtYxgb3Ti+JO/wCYvhbAb/U
 ARG V8=14.0.365.4
-ARG ZIG_V8=v0.3.4
+ARG ZIG_V8=v0.3.7
 ARG TARGETPLATFORM
 
 RUN apt-get update -yq && \

build.zig

@@ -85,6 +85,15 @@ pub fn build(b: *Build) !void {
         break :blk mod;
     };
 
+    // Check compilation
+    const check = b.step("check", "Check if lightpanda compiles");
+
+    const check_lib = b.addLibrary(.{
+        .name = "lightpanda_check",
+        .root_module = lightpanda_module,
+    });
+    check.dependOn(&check_lib.step);
+
     {
         // browser
         const exe = b.addExecutable(.{
@@ -103,6 +112,12 @@ pub fn build(b: *Build) !void {
         });
         b.installArtifact(exe);
 
+        const exe_check = b.addLibrary(.{
+            .name = "lightpanda_exe_check",
+            .root_module = exe.root_module,
+        });
+        check.dependOn(&exe_check.step);
+
         const run_cmd = b.addRunArtifact(exe);
         if (b.args) |args| {
             run_cmd.addArgs(args);
@@ -132,6 +147,12 @@ pub fn build(b: *Build) !void {
         });
         b.installArtifact(exe);
 
+        const exe_check = b.addLibrary(.{
+            .name = "snapshot_creator_check",
+            .root_module = exe.root_module,
+        });
+        check.dependOn(&exe_check.step);
+
         const run_cmd = b.addRunArtifact(exe);
         if (b.args) |args| {
             run_cmd.addArgs(args);
@@ -170,6 +191,12 @@ pub fn build(b: *Build) !void {
         });
         b.installArtifact(exe);
 
+        const exe_check = b.addLibrary(.{
+            .name = "legacy_test_check",
+            .root_module = exe.root_module,
+        });
+        check.dependOn(&exe_check.step);
+
         const run_cmd = b.addRunArtifact(exe);
         if (b.args) |args| {
             run_cmd.addArgs(args);
@@ -728,8 +755,17 @@ fn resolveVersion(b: *std.Build) std.SemanticVersion {
         };
     }
 
+    const pre_version = b.option([]const u8, "pre_version", "Override the pre version of this build");
+    const pre = blk: {
+        if (pre_version) |pre| {
+            break :blk pre;
+        }
+
+        break :blk lightpanda_version.pre;
+    };
+
     // If it's a stable release (no pre or build metadata in build.zig.zon), use it as is
-    if (lightpanda_version.pre == null and lightpanda_version.build == null) return lightpanda_version;
+    if (pre == null and lightpanda_version.build == null) return lightpanda_version;
 
     // For dev/nightly versions, calculate the commit count and hash
     const git_hash_raw = runGit(b, &.{ "rev-parse", "--short", "HEAD" }) catch return lightpanda_version;
@@ -742,7 +778,7 @@ fn resolveVersion(b: *std.Build) std.SemanticVersion {
         .major = lightpanda_version.major,
         .minor = lightpanda_version.minor,
         .patch = lightpanda_version.patch,
-        .pre = b.fmt("{s}.{s}", .{ lightpanda_version.pre.?, commit_count }),
+        .pre = b.fmt("{s}.{s}", .{ pre.?, commit_count }),
         .build = commit_hash,
     };
 }

build.zig.zon

@@ -5,8 +5,8 @@
     .minimum_zig_version = "0.15.2",
     .dependencies = .{
         .v8 = .{
-            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/refs/tags/v0.3.4.tar.gz",
-            .hash = "v8-0.0.0-xddH6_F3BAAiFvKY6R1H-gkuQlk19BkDQ0--uZuTrSup",
+            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/refs/tags/v0.3.7.tar.gz",
+            .hash = "v8-0.0.0-xddH67uBBAD95hWsPQz3Ni1PlZjdywtPXrGUAp8rSKco",
         },
         // .v8 = .{ .path = "../zig-v8-fork" },
         .brotli = .{

src/Config.zig

@@ -247,7 +247,7 @@ pub const Fetch = struct {
     with_frames: bool = false,
     strip: dump.Opts.Strip = .{},
     wait_ms: u32 = 5000,
-    wait_until: WaitUntil = .load,
+    wait_until: WaitUntil = .done,
 };
 
 pub const Common = struct {
@@ -665,7 +665,7 @@ fn parseFetchArgs(
     var common: Common = .{};
     var strip: dump.Opts.Strip = .{};
     var wait_ms: u32 = 5000;
-    var wait_until: WaitUntil = .load;
+    var wait_until: WaitUntil = .done;
 
     while (args.next()) |opt| {
         if (std.mem.eql(u8, "--wait-ms", opt) or std.mem.eql(u8, "--wait_ms", opt)) {

src/Server.zig

@@ -27,7 +27,7 @@ const ArenaAllocator = std.heap.ArenaAllocator;
 const log = @import("log.zig");
 const App = @import("App.zig");
 const Config = @import("Config.zig");
-const CDP = @import("cdp/cdp.zig").CDP;
+const CDP = @import("cdp/CDP.zig");
 const Net = @import("network/websocket.zig");
 const HttpClient = @import("browser/HttpClient.zig");
 
@@ -212,7 +212,7 @@ pub const Client = struct {
     http: *HttpClient,
     ws: Net.WsConnection,
 
-    fn init(
+    pub fn init(
         socket: posix.socket_t,
         allocator: Allocator,
         app: *App,
@@ -250,7 +250,7 @@ pub const Client = struct {
         self.ws.shutdown();
     }
 
-    fn deinit(self: *Client) void {
+    pub fn deinit(self: *Client) void {
         switch (self.mode) {
             .cdp => |*cdp| cdp.deinit(),
             .http => {},
@@ -461,7 +461,7 @@ pub const Client = struct {
 
     fn upgradeConnection(self: *Client, request: []u8) !void {
         try self.ws.upgrade(request);
-        self.mode = .{ .cdp = try CDP.init(self.app, self.http, self) };
+        self.mode = .{ .cdp = try CDP.init(self) };
     }
 
     fn writeHTTPErrorResponse(self: *Client, comptime status: u16, comptime body: []const u8) void {

src/browser/Page.zig

@@ -300,7 +300,9 @@ pub fn init(self: *Page, frame_id: u32, session: *Session, parent: ?*Page) !void
         ._performance = Performance.init(),
         ._screen = screen,
         ._visual_viewport = visual_viewport,
+        ._cross_origin_wrapper = undefined,
     });
+    self.window._cross_origin_wrapper = .{ .window = self.window };
 
     self._style_manager = try StyleManager.init(self);
     errdefer self._style_manager.deinit();
@@ -3587,12 +3589,7 @@ test "WebApi: Page" {
 }
 
 test "WebApi: Frames" {
-    // TOO FLAKY, disabled for now
-
-    // const filter: testing.LogFilter = .init(&.{.js});
-    // defer filter.deinit();
-
-    // try testing.htmlRunner("frames", .{});
+    try testing.htmlRunner("frames", .{});
 }
 
 test "WebApi: Integration" {

src/browser/URL.zig

@@ -357,25 +357,38 @@ pub fn isHTTPS(raw: [:0]const u8) bool {
 
 pub fn getHostname(raw: [:0]const u8) []const u8 {
     const host = getHost(raw);
-    const pos = std.mem.lastIndexOfScalar(u8, host, ':') orelse return host;
-    return host[0..pos];
+    const port_sep = findPortSeparator(host) orelse return host;
+    return host[0..port_sep];
 }
 
 pub fn getPort(raw: [:0]const u8) []const u8 {
     const host = getHost(raw);
-    const pos = std.mem.lastIndexOfScalar(u8, host, ':') orelse return "";
+    const port_sep = findPortSeparator(host) orelse return "";
+    return host[port_sep + 1 ..];
+}
 
-    if (pos + 1 >= host.len) {
-        return "";
+// Finds the colon separating host from port, handling IPv6 bracket notation.
+// For IPv6 like "[::1]:8080", returns position of ":" after "]".
+// For IPv6 like "[::1]" (no port), returns null.
+// For regular hosts, returns position of last ":" if followed by digits.
+fn findPortSeparator(host: []const u8) ?usize {
+    if (host.len > 0 and host[0] == '[') {
+        // IPv6: find closing bracket, port separator must be after it
+        const bracket_end = std.mem.indexOfScalar(u8, host, ']') orelse return null;
+        if (bracket_end + 1 < host.len and host[bracket_end + 1] == ':') {
+            return bracket_end + 1;
+        }
+        return null;
     }
 
+    // Regular host: find last colon and verify it's followed by digits
+    const pos = std.mem.lastIndexOfScalar(u8, host, ':') orelse return null;
+    if (pos + 1 >= host.len) return null;
+
     for (host[pos + 1 ..]) |c| {
-        if (c < '0' or c > '9') {
-            return "";
-        }
+        if (c < '0' or c > '9') return null;
     }
-
-    return host[pos + 1 ..];
+    return pos;
 }
 
 pub fn getSearch(raw: [:0]const u8) []const u8 {
@@ -403,21 +416,12 @@ pub fn getOrigin(allocator: Allocator, raw: [:0]const u8) !?[]const u8 {
         return null;
     }
 
-    var authority_start = scheme_end + 3;
-    const has_user_info = if (std.mem.indexOf(u8, raw[authority_start..], "@")) |pos| blk: {
-        authority_start += pos + 1;
-        break :blk true;
-    } else false;
-
-    // Find end of authority (start of path/query/fragment or end of string)
-    const authority_end_relative = std.mem.indexOfAny(u8, raw[authority_start..], "/?#");
-    const authority_end = if (authority_end_relative) |end|
-        authority_start + end
-    else
-        raw.len;
+    const auth = parseAuthority(raw) orelse return null;
+    const has_user_info = auth.has_user_info;
+    const authority_end = auth.host_end;
 
     // Check for port in the host:port section
-    const host_part = raw[authority_start..authority_end];
+    const host_part = auth.getHost(raw);
     if (std.mem.lastIndexOfScalar(u8, host_part, ':')) |colon_pos_in_host| {
         const port = host_part[colon_pos_in_host + 1 ..];
 
@@ -458,31 +462,18 @@ pub fn getOrigin(allocator: Allocator, raw: [:0]const u8) !?[]const u8 {
 }
 
 fn getUserInfo(raw: [:0]const u8) ?[]const u8 {
-    const scheme_end = std.mem.indexOf(u8, raw, "://") orelse return null;
+    const auth = parseAuthority(raw) orelse return null;
+    if (!auth.has_user_info) return null;
+
+    // User info is from authority_start to host_start - 1 (excluding the @)
+    const scheme_end = std.mem.indexOf(u8, raw, "://").?;
     const authority_start = scheme_end + 3;
-
-    const pos = std.mem.indexOfScalar(u8, raw[authority_start..], '@') orelse return null;
-    const path_start = std.mem.indexOfScalarPos(u8, raw, authority_start, '/') orelse raw.len;
-
-    const full_pos = authority_start + pos;
-    if (full_pos < path_start) {
-        return raw[authority_start..full_pos];
-    }
-
-    return null;
+    return raw[authority_start .. auth.host_start - 1];
 }
 
 pub fn getHost(raw: [:0]const u8) []const u8 {
-    const scheme_end = std.mem.indexOf(u8, raw, "://") orelse return "";
-
-    var authority_start = scheme_end + 3;
-    if (std.mem.indexOf(u8, raw[authority_start..], "@")) |pos| {
-        authority_start += pos + 1;
-    }
-
-    const authority = raw[authority_start..];
-    const path_start = std.mem.indexOfAny(u8, authority, "/?#") orelse return authority;
-    return authority[0..path_start];
+    const auth = parseAuthority(raw) orelse return "";
+    return auth.getHost(raw);
 }
 
 // Returns true if these two URLs point to the same document.
@@ -761,6 +752,47 @@ pub fn unescape(arena: Allocator, input: []const u8) ![]const u8 {
     return result.items;
 }
 
+const AuthorityInfo = struct {
+    host_start: usize,
+    host_end: usize,
+    has_user_info: bool,
+
+    fn getHost(self: AuthorityInfo, raw: []const u8) []const u8 {
+        return raw[self.host_start..self.host_end];
+    }
+};
+
+// Parses the authority component of a URL, correctly handling userinfo.
+// Returns null if the URL doesn't have a valid scheme (no "://").
+// SECURITY: Only looks for @ within the authority portion (before /?#)
+// to prevent path-based @ injection attacks.
+fn parseAuthority(raw: []const u8) ?AuthorityInfo {
+    const scheme_end = std.mem.indexOf(u8, raw, "://") orelse return null;
+    const authority_start = scheme_end + 3;
+
+    // Find end of authority FIRST (start of path/query/fragment or end of string)
+    const authority_end = if (std.mem.indexOfAny(u8, raw[authority_start..], "/?#")) |end|
+        authority_start + end
+    else
+        raw.len;
+
+    // Only look for @ within the authority portion, not in path/query/fragment
+    const authority_portion = raw[authority_start..authority_end];
+    if (std.mem.indexOf(u8, authority_portion, "@")) |pos| {
+        return .{
+            .host_start = authority_start + pos + 1,
+            .host_end = authority_end,
+            .has_user_info = true,
+        };
+    }
+
+    return .{
+        .host_start = authority_start,
+        .host_end = authority_end,
+        .has_user_info = false,
+    };
+}
+
 const testing = @import("../testing.zig");
 test "URL: isCompleteHTTPUrl" {
     try testing.expectEqual(true, isCompleteHTTPUrl("http://example.com/about"));
@@ -1429,6 +1461,42 @@ test "URL: getHost" {
     try testing.expectEqualSlices(u8, "example.com", getHost("https://user:pass@example.com/page"));
     try testing.expectEqualSlices(u8, "example.com:8080", getHost("https://user:pass@example.com:8080/page"));
     try testing.expectEqualSlices(u8, "", getHost("not-a-url"));
+
+    // SECURITY: @ in path must NOT be treated as userinfo separator
+    try testing.expectEqualSlices(u8, "evil.example.com", getHost("http://evil.example.com/@victim.example.com/"));
+    try testing.expectEqualSlices(u8, "evil.example.com", getHost("https://evil.example.com/path/@victim.example.com"));
+
+    // IPv6 addresses
+    try testing.expectEqualSlices(u8, "[::1]:8080", getHost("http://[::1]:8080/path"));
+    try testing.expectEqualSlices(u8, "[::1]", getHost("http://[::1]/path"));
+    try testing.expectEqualSlices(u8, "[2001:db8::1]", getHost("https://[2001:db8::1]/"));
+}
+
+test "URL: getHostname" {
+    // Regular hosts
+    try testing.expectEqualSlices(u8, "example.com", getHostname("https://example.com:8080/path"));
+    try testing.expectEqualSlices(u8, "example.com", getHostname("https://example.com/path"));
+
+    // IPv6 with port
+    try testing.expectEqualSlices(u8, "[::1]", getHostname("http://[::1]:8080/path"));
+
+    // IPv6 without port - must return full bracket notation
+    try testing.expectEqualSlices(u8, "[::1]", getHostname("http://[::1]/path"));
+    try testing.expectEqualSlices(u8, "[2001:db8::1]", getHostname("https://[2001:db8::1]/"));
+}
+
+test "URL: getPort" {
+    // Regular hosts
+    try testing.expectEqualSlices(u8, "8080", getPort("https://example.com:8080/path"));
+    try testing.expectEqualSlices(u8, "", getPort("https://example.com/path"));
+
+    // IPv6 with port
+    try testing.expectEqualSlices(u8, "8080", getPort("http://[::1]:8080/path"));
+    try testing.expectEqualSlices(u8, "3000", getPort("http://[2001:db8::1]:3000/"));
+
+    // IPv6 without port - colons inside brackets must not be treated as port separator
+    try testing.expectEqualSlices(u8, "", getPort("http://[::1]/path"));
+    try testing.expectEqualSlices(u8, "", getPort("https://[2001:db8::1]/"));
 }
 
 test "URL: setPathname percent-encodes" {
@@ -1449,3 +1517,56 @@ test "URL: setPathname percent-encodes" {
     const result3 = try setPathname("https://example.com/path?a=b#hash", "/new path", allocator);
     try testing.expectEqualSlices(u8, "https://example.com/new%20path?a=b#hash", result3);
 }
+
+test "URL: getOrigin" {
+    defer testing.reset();
+
+    const Case = struct {
+        url: [:0]const u8,
+        expected: ?[]const u8,
+    };
+
+    const cases = [_]Case{
+        // Basic HTTP/HTTPS origins
+        .{ .url = "http://example.com/path", .expected = "http://example.com" },
+        .{ .url = "https://example.com/path", .expected = "https://example.com" },
+        .{ .url = "https://example.com:8080/path", .expected = "https://example.com:8080" },
+
+        // Default ports should be stripped
+        .{ .url = "http://example.com:80/path", .expected = "http://example.com" },
+        .{ .url = "https://example.com:443/path", .expected = "https://example.com" },
+
+        // User info should be stripped from origin
+        .{ .url = "http://user:pass@example.com/path", .expected = "http://example.com" },
+        .{ .url = "https://user@example.com:8080/path", .expected = "https://example.com:8080" },
+
+        // Non-HTTP schemes return null
+        .{ .url = "ftp://example.com/path", .expected = null },
+        .{ .url = "file:///path/to/file", .expected = null },
+        .{ .url = "about:blank", .expected = null },
+
+        // Query and fragment should not affect origin
+        .{ .url = "https://example.com?query=1", .expected = "https://example.com" },
+        .{ .url = "https://example.com#fragment", .expected = "https://example.com" },
+        .{ .url = "https://example.com/path?q=1#frag", .expected = "https://example.com" },
+
+        // SECURITY: @ in path must NOT be treated as userinfo separator
+        // This would be a Same-Origin Policy bypass if mishandled
+        .{ .url = "http://evil.example.com/@victim.example.com/", .expected = "http://evil.example.com" },
+        .{ .url = "https://evil.example.com/path/@victim.example.com/steal", .expected = "https://evil.example.com" },
+        .{ .url = "http://evil.example.com/@victim.example.com:443/", .expected = "http://evil.example.com" },
+
+        // @ in query/fragment must also not affect origin
+        .{ .url = "https://example.com/path?user=foo@bar.com", .expected = "https://example.com" },
+        .{ .url = "https://example.com/path#user@host", .expected = "https://example.com" },
+    };
+
+    for (cases) |case| {
+        const result = try getOrigin(testing.arena_allocator, case.url);
+        if (case.expected) |expected| {
+            try testing.expectString(expected, result.?);
+        } else {
+            try testing.expectEqual(null, result);
+        }
+    }
+}

src/browser/interactive.zig

@@ -36,6 +36,7 @@ pub const InteractivityType = enum {
 };
 
 pub const InteractiveElement = struct {
+    backendNodeId: ?u32 = null,
     node: *Node,
     tag_name: []const u8,
     role: ?[]const u8,
@@ -55,6 +56,11 @@ pub const InteractiveElement = struct {
     pub fn jsonStringify(self: *const InteractiveElement, jw: anytype) !void {
         try jw.beginObject();
 
+        if (self.backendNodeId) |id| {
+            try jw.objectField("backendNodeId");
+            try jw.write(id);
+        }
+
         try jw.objectField("tagName");
         try jw.write(self.tag_name);
 
@@ -123,6 +129,15 @@ pub const InteractiveElement = struct {
     }
 };
 
+/// Populate backendNodeId on each interactive element by registering
+/// their nodes in the given registry. Works with both CDP and MCP registries.
+pub fn registerNodes(elements: []InteractiveElement, registry: anytype) !void {
+    for (elements) |*el| {
+        const registered = try registry.register(el.node);
+        el.backendNodeId = registered.id;
+    }
+}
+
 /// Collect all interactive elements under `root`.
 pub fn collectInteractiveElements(
     root: *Node,

src/browser/js/Caller.zig

@@ -505,6 +505,7 @@ pub const Function = struct {
     pub const Opts = struct {
         noop: bool = false,
         static: bool = false,
+        deletable: bool = true,
         dom_exception: bool = false,
         as_typed_array: bool = false,
         null_as_undefined: bool = false,

src/browser/js/Snapshot.zig

@@ -137,7 +137,7 @@ pub fn create() !Snapshot {
         defer v8.v8__HandleScope__DESTRUCT(&handle_scope);
 
         // Create templates (constructors only) FIRST
-        var templates: [JsApis.len]*v8.FunctionTemplate = undefined;
+        var templates: [JsApis.len]*const v8.FunctionTemplate = undefined;
         inline for (JsApis, 0..) |JsApi, i| {
             @setEvalBranchQuota(10_000);
             templates[i] = generateConstructor(JsApi, isolate);
@@ -419,7 +419,7 @@ fn collectExternalReferences() [countExternalReferences()]isize {
 // via `new ClassName()` - but they could, for example, be created in
 // Zig and returned from a function call, which is why we need the
 // FunctionTemplate.
-fn generateConstructor(comptime JsApi: type, isolate: *v8.Isolate) *v8.FunctionTemplate {
+fn generateConstructor(comptime JsApi: type, isolate: *v8.Isolate) *const v8.FunctionTemplate {
     const callback = blk: {
         if (@hasDecl(JsApi, "constructor")) {
             break :blk JsApi.constructor.func;
@@ -429,7 +429,7 @@ fn generateConstructor(comptime JsApi: type, isolate: *v8.Isolate) *v8.FunctionT
         break :blk illegalConstructorCallback;
     };
 
-    const template = @constCast(v8.v8__FunctionTemplate__New__DEFAULT2(isolate, callback).?);
+    const template = v8.v8__FunctionTemplate__New__DEFAULT2(isolate, callback).?;
     {
         const internal_field_count = comptime countInternalFields(JsApi);
         if (internal_field_count > 0) {
@@ -482,10 +482,15 @@ pub fn countInternalFields(comptime JsApi: type) u8 {
 }
 
 // Attaches JsApi members to the prototype template (normal case)
-fn attachClass(comptime JsApi: type, isolate: *v8.Isolate, template: *v8.FunctionTemplate) void {
+fn attachClass(comptime JsApi: type, isolate: *v8.Isolate, template: *const v8.FunctionTemplate) void {
     const instance = v8.v8__FunctionTemplate__InstanceTemplate(template);
     const prototype = v8.v8__FunctionTemplate__PrototypeTemplate(template);
 
+    // Create a signature that validates the receiver is an instance of this template.
+    // This prevents crashes when JavaScript extracts a getter/method and calls it
+    // with the wrong `this` (e.g., documentGetter.call(null)).
+    const signature = v8.v8__Signature__New(isolate, template);
+
     const declarations = @typeInfo(JsApi).@"struct".decls;
     var has_named_index_getter = false;
 
@@ -497,23 +502,47 @@ fn attachClass(comptime JsApi: type, isolate: *v8.Isolate, template: *v8.Functio
         switch (definition) {
             bridge.Accessor => {
                 const js_name = v8.v8__String__NewFromUtf8(isolate, name.ptr, v8.kNormal, @intCast(name.len));
-                const getter_callback = @constCast(v8.v8__FunctionTemplate__New__Config(isolate, &.{ .callback = value.getter }).?);
+                const getter_signature = if (value.static) null else signature;
+                const getter_callback = v8.v8__FunctionTemplate__New__Config(isolate, &.{
+                    .callback = value.getter,
+                    .signature = getter_signature,
+                }).?;
+                const setter_callback = if (value.setter) |setter|
+                    v8.v8__FunctionTemplate__New__Config(isolate, &.{
+                        .callback = setter,
+                        .signature = getter_signature,
+                    }).?
+                else
+                    null;
+
+                var attribute: v8.PropertyAttribute = 0;
                 if (value.setter == null) {
-                    if (value.static) {
-                        v8.v8__Template__SetAccessorProperty__DEFAULT(@ptrCast(template), js_name, getter_callback);
-                    } else {
-                        v8.v8__ObjectTemplate__SetAccessorProperty__DEFAULT(prototype, js_name, getter_callback);
-                    }
+                    attribute |= v8.ReadOnly;
+                }
+                if (value.deletable == false) {
+                    attribute |= v8.DontDelete;
+                }
+
+                if (value.static) {
+                    // Static accessors: use Template's SetAccessorProperty
+                    v8.v8__Template__SetAccessorProperty(@ptrCast(template), js_name, getter_callback, setter_callback, attribute);
                 } else {
-                    if (comptime IS_DEBUG) {
-                        std.debug.assert(value.static == false);
-                    }
-                    const setter_callback = @constCast(v8.v8__FunctionTemplate__New__Config(isolate, &.{ .callback = value.setter.? }).?);
-                    v8.v8__ObjectTemplate__SetAccessorProperty__DEFAULT2(prototype, js_name, getter_callback, setter_callback);
+                    v8.v8__ObjectTemplate__SetAccessorProperty__Config(prototype, &.{
+                        .key = js_name,
+                        .getter = getter_callback,
+                        .setter = setter_callback,
+                        .attribute = attribute,
+                    });
                 }
             },
             bridge.Function => {
-                const function_template = @constCast(v8.v8__FunctionTemplate__New__Config(isolate, &.{ .callback = value.func, .length = value.arity }).?);
+                // For non-static functions, use the signature to validate the receiver
+                const func_signature = if (value.static) null else signature;
+                const function_template = v8.v8__FunctionTemplate__New__Config(isolate, &.{
+                    .callback = value.func,
+                    .length = value.arity,
+                    .signature = func_signature,
+                }).?;
                 const js_name = v8.v8__String__NewFromUtf8(isolate, name.ptr, v8.kNormal, @intCast(name.len));
                 if (value.static) {
                     v8.v8__Template__Set(@ptrCast(template), js_name, @ptrCast(function_template), v8.None);
@@ -551,7 +580,7 @@ fn attachClass(comptime JsApi: type, isolate: *v8.Isolate, template: *v8.Functio
                 has_named_index_getter = true;
             },
             bridge.Iterator => {
-                const function_template = @constCast(v8.v8__FunctionTemplate__New__Config(isolate, &.{ .callback = value.func }).?);
+                const function_template = v8.v8__FunctionTemplate__New__Config(isolate, &.{ .callback = value.func }).?;
                 const js_name = if (value.async)
                     v8.v8__Symbol__GetAsyncIterator(isolate)
                 else

src/browser/js/bridge.zig

@@ -198,6 +198,7 @@ pub const Function = struct {
 
 pub const Accessor = struct {
     static: bool = false,
+    deletable: bool = true,
     cache: ?Caller.Function.Opts.Caching = null,
     getter: ?*const fn (?*const v8.FunctionCallbackInfo) callconv(.c) void = null,
     setter: ?*const fn (?*const v8.FunctionCallbackInfo) callconv(.c) void = null,
@@ -206,6 +207,7 @@ pub const Accessor = struct {
         var accessor = Accessor{
             .cache = opts.cache,
             .static = opts.static,
+            .deletable = opts.deletable,
         };
 
         if (@typeInfo(@TypeOf(getter)) != .null) {
@@ -851,6 +853,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/event/InputEvent.zig"),
     @import("../webapi/event/PromiseRejectionEvent.zig"),
     @import("../webapi/event/SubmitEvent.zig"),
+    @import("../webapi/event/FormDataEvent.zig"),
     @import("../webapi/MessageChannel.zig"),
     @import("../webapi/MessagePort.zig"),
     @import("../webapi/media/MediaError.zig"),

src/browser/links.zig

@@ -0,0 +1,54 @@
+// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+
+const Element = @import("webapi/Element.zig");
+const Node = @import("webapi/Node.zig");
+const Page = @import("Page.zig");
+const Selector = @import("webapi/selector/Selector.zig");
+
+const Allocator = std.mem.Allocator;
+
+/// Collect all links (href attributes from anchor tags) under `root`.
+/// Returns a slice of strings allocated with `arena`.
+pub fn collectLinks(arena: Allocator, root: *Node, page: *Page) ![]const []const u8 {
+    var links: std.ArrayList([]const u8) = .empty;
+
+    if (Selector.querySelectorAll(root, "a[href]", page)) |list| {
+        defer list.deinit(page._session);
+
+        for (list._nodes) |node| {
+            if (node.is(Element.Html.Anchor)) |anchor| {
+                const href = anchor.getHref(page) catch |err| {
+                    @import("../lightpanda.zig").log.err(.app, "resolve href failed", .{ .err = err });
+                    continue;
+                };
+
+                if (href.len > 0) {
+                    try links.append(arena, href);
+                }
+            }
+        }
+    } else |err| {
+        @import("../lightpanda.zig").log.err(.app, "query links failed", .{ .err = err });
+        return err;
+    }
+
+    return links.items;
+}

src/browser/tests/canvas/canvas_rendering_context_2d.html

@@ -125,6 +125,19 @@
 </script>
 
 
+<script id="CanvasRenderingContext2D#canvas">
+{
+  const element = document.createElement("canvas");
+  const ctx = element.getContext("2d");
+  testing.expectEqual(ctx.canvas, element);
+  // Setting dimensions via ctx.canvas should update the element.
+  ctx.canvas.width = 40;
+  ctx.canvas.height = 25;
+  testing.expectEqual(element.width, 40);
+  testing.expectEqual(element.height, 25);
+}
+</script>
+
 <script id="getter">
 {
   const element = document.createElement("canvas");

src/browser/tests/frames/frames.html

@@ -118,24 +118,24 @@
   }
 </script>
 
-<script id=link_click>
-  testing.async(async (restore) => {
-    let f6;
-    await new Promise((resolve) => {
-      let count = 0;
-      f6 = document.createElement('iframe');
-      f6.id = 'f6';
-      f6.addEventListener('load', () => {
-        if (++count == 2) {
-          resolve();
-          return;
-        }
-        f6.contentDocument.querySelector('#link').click();
-      });
-      f6.src = "support/with_link.html";
-      document.documentElement.appendChild(f6);
-    });
-    restore();
+<script id=link_click type=module>
+  const state = await testing.async();
+
+  let count = 0;
+  let f6 = document.createElement('iframe');
+  f6.id = 'f6';
+  f6.addEventListener('load', () => {
+    if (++count == 2) {
+      state.resolve();
+      return;
+    }
+    f6.contentDocument.querySelector('#link').click();
+  });
+
+  f6.src = 'support/with_link.html';
+  document.documentElement.appendChild(f6);
+
+  await state.done(() => {
     testing.expectEqual("<html><head></head><body>It was clicked!\n</body></html>", f6.contentDocument.documentElement.outerHTML);
   });
 </script>

src/browser/tests/frames/post_message.html

@@ -7,7 +7,6 @@
 {
   let reply = null;
   window.addEventListener('message', (e) => {
-    console.warn('reply')
     reply = e.data;
   });
 

src/browser/tests/frames/support/message_receiver.html

@@ -1,7 +1,6 @@
 <!DOCTYPE html>
 <script>
   window.addEventListener('message', (e) => {
-    console.warn('Frame Message', e.data);
     if (e.data === 'ping') {
       window.top.postMessage({data: 'pong', origin: e.origin}, '*');
     }

src/browser/tests/net/form_data.html

@@ -734,3 +734,101 @@
   testing.expectEqual([['field', 'data'], ['x', '0'], ['y', '0']], entries);
 }
 </script>
+
+<script id=formDataEventFires>
+{
+  // formdata event fires on the form when FormData is constructed with a form
+  const form = document.createElement('form');
+
+  const input = document.createElement('input');
+  input.name = 'field';
+  input.value = 'hello';
+  form.appendChild(input);
+
+  let eventFired = false;
+  let receivedFormData = null;
+
+  form.addEventListener('formdata', (e) => {
+    eventFired = true;
+    receivedFormData = e.formData;
+  });
+
+  const fd = new FormData(form);
+  testing.expectEqual(true, eventFired);
+  testing.expectEqual(fd, receivedFormData);
+}
+</script>
+
+<script id=formDataEventNotFiredWithoutForm>
+{
+  // formdata event should NOT fire when FormData is constructed without a form
+  const fd = new FormData();
+  fd.append('a', '1');
+  testing.expectEqual('1', fd.get('a'));
+}
+</script>
+
+<script id=formDataEventBubbles>
+{
+  // formdata event should bubble
+  const container = document.createElement('div');
+  const form = document.createElement('form');
+  container.appendChild(form);
+  document.body.appendChild(container);
+
+  const input = document.createElement('input');
+  input.name = 'x';
+  input.value = '1';
+  form.appendChild(input);
+
+  let bubbled = false;
+  container.addEventListener('formdata', () => {
+    bubbled = true;
+  });
+
+  const fd = new FormData(form);
+  testing.expectEqual(true, bubbled);
+
+  document.body.removeChild(container);
+}
+</script>
+
+<script id=formDataEventNotCancelable>
+{
+  // formdata event should not be cancelable
+  const form = document.createElement('form');
+
+  const input = document.createElement('input');
+  input.name = 'key';
+  input.value = 'val';
+  form.appendChild(input);
+
+  let cancelable = null;
+  form.addEventListener('formdata', (e) => {
+    cancelable = e.cancelable;
+  });
+
+  const fd = new FormData(form);
+  testing.expectEqual(false, cancelable);
+}
+</script>
+
+<script id=formDataEventModifyFormData>
+{
+  // Listeners can modify formData during the event
+  const form = document.createElement('form');
+
+  const input = document.createElement('input');
+  input.name = 'original';
+  input.value = 'data';
+  form.appendChild(input);
+
+  form.addEventListener('formdata', (e) => {
+    e.formData.append('added', 'by-listener');
+  });
+
+  const fd = new FormData(form);
+  testing.expectEqual('data', fd.get('original'));
+  testing.expectEqual('by-listener', fd.get('added'));
+}
+</script>

src/browser/tests/testing.js

@@ -4,6 +4,7 @@
   let eventuallies = [];
   let async_capture = null;
   let current_script_id = null;
+  let async_pending = 0;
 
   function expectTrue(actual) {
      expectEqual(true, actual);
@@ -64,6 +65,25 @@
   }
 
   async function async(cb) {
+    if (cb == undefined) {
+      let resolve = null
+      const promise = new Promise((r) => { resolve = r});
+      async_pending += 1;
+
+      return {
+        promise: promise,
+        resolve: resolve,
+        capture: {script_id: document.currentScript.id, stack: new Error().stack},
+        done: async function(cb) {
+          await this.promise;
+          async_pending -= 1;
+          async_capture = this.capture;
+          cb();
+          async_capture = false;
+        }
+      };
+    }
+
     let capture = {script_id: document.currentScript.id, stack: new Error().stack};
     await cb(() => { async_capture = capture; });
     async_capture = null;
@@ -74,6 +94,10 @@
       throw new Error('Failed');
     }
 
+    if (async_pending > 0) {
+      return false;
+    }
+
     for (let e of eventuallies) {
       current_script_id = e.script_id;
       e.callback();
@@ -97,6 +121,8 @@
          throw new Error(`script id: '${script_id}' failed: ${status || 'no assertions'}`);
       }
     }
+
+    return true;
   }
 
   const IS_TEST_RUNNER = window.navigator.userAgent.startsWith("Lightpanda/");

src/browser/tests/window/cross_origin.html

@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+
+<iframe src=support/frame1.html></iframe>
+
+<script id=post_message type=module>
+  const state = await testing.async();
+
+{
+  const ALT_BASE = testing.BASE_URL.replace('127.0.0.1', 'localhost');
+
+  {
+    let iframe2 = document.createElement('iframe');
+    iframe2.src = ALT_BASE + 'window/support/frame1.html';
+    document.documentElement.appendChild(iframe2);
+  }
+
+  {
+    let iframe3 = document.createElement('iframe');
+    iframe3.src = ALT_BASE + 'window/support/frame2.html';
+    document.documentElement.appendChild(iframe3);
+  }
+
+  let captures = [];
+  window.addEventListener('message', (e) => {
+    captures.push(e.data);
+    if (captures.length == 3) {
+      state.resolve();
+    }
+  });
+
+  await state.done(() => {
+    const expected_urls = [
+      testing.BASE_URL + 'window/support/frame1.html',
+      ALT_BASE + 'window/support/frame1.html',
+      ALT_BASE + 'window/support/frame2.html',
+    ];
+
+    // No strong order guarantee for messaages, and we don't care about the order
+    // so long as it's the correct data.
+    testing.expectEqual(expected_urls.sort(), captures.map((c) => {return c.url}).sort());
+    captures.forEach((c) => {
+      if (c.url.includes(testing.BASE_URL)) {
+        testing.expectEqual(false, c.document_is_undefined);
+      } else {
+        testing.expectEqual(true, c.document_is_undefined);
+      }
+    });
+  });
+}
+</script>

src/browser/tests/window/support/frame1.html

@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<script>
+  window.parent.postMessage({
+    url: location.toString(),
+    document_is_undefined: window.parent.document === undefined,
+  }, '*')
+</script>

src/browser/tests/window/support/frame2.html

@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<script>
+  window.top.postMessage({
+    url: location.toString(),
+    document_is_undefined: window.top.document === undefined,
+  }, '*')
+</script>

src/browser/tests/window/window.html

@@ -262,6 +262,31 @@
   }
 </script>
 
+<script id=cached_getter_wrong_this>
+  // Test that extracting a cached property getter and calling it with wrong `this`
+  // doesn't crash (V8 internal field out of bounds). V8's Signature validation
+  // should throw "Illegal invocation" for wrong receiver types.
+  const documentGetter = Object.getOwnPropertyDescriptor(Window.prototype, 'document').get;
+
+  // Verify we get an error with wrong this values
+  let errorCount = 0;
+  const testValues = [{}, null, undefined, 42, 'string', [], () => {}];
+  for (const val of testValues) {
+    try {
+      documentGetter.call(val);
+    } catch (e) {
+      if (e.message.includes('Illegal invocation')) {
+        errorCount++;
+      }
+    }
+  }
+  // At least some should throw (null/undefined/primitives get coerced in sloppy mode)
+  testing.expectEqual(true, errorCount > 0);
+
+  // Calling with correct this should still work
+  testing.expectEqual(document, documentGetter.call(window));
+</script>
+
 <script id=unhandled_rejection>
   {
     let unhandledCalled = 0;

src/browser/webapi/Event.zig

@@ -77,6 +77,7 @@ pub const Type = union(enum) {
     ui_event: *@import("event/UIEvent.zig"),
     promise_rejection_event: *@import("event/PromiseRejectionEvent.zig"),
     submit_event: *@import("event/SubmitEvent.zig"),
+    form_data_event: *@import("event/FormDataEvent.zig"),
 };
 
 pub const Options = struct {
@@ -176,6 +177,7 @@ pub fn is(self: *Event, comptime T: type) ?*T {
         .pop_state_event => |e| return if (T == @import("event/PopStateEvent.zig")) e else null,
         .promise_rejection_event => |e| return if (T == @import("event/PromiseRejectionEvent.zig")) e else null,
         .submit_event => |e| return if (T == @import("event/SubmitEvent.zig")) e else null,
+        .form_data_event => |e| return if (T == @import("event/FormDataEvent.zig")) e else null,
         .ui_event => |e| {
             if (T == @import("event/UIEvent.zig")) {
                 return e;

src/browser/webapi/IntersectionObserver.zig

@@ -25,6 +25,8 @@ const Allocator = std.mem.Allocator;
 
 const Page = @import("../Page.zig");
 const Session = @import("../Session.zig");
+
+const Node = @import("Node.zig");
 const Element = @import("Element.zig");
 const DOMRect = @import("DOMRect.zig");
 
@@ -55,7 +57,7 @@ var zero_rect: DOMRect = .{
 };
 
 pub const ObserverInit = struct {
-    root: ?*Element = null,
+    root: ?*Node = null,
     rootMargin: ?[]const u8 = null,
     threshold: Threshold = .{ .scalar = 0.0 },
 
@@ -81,11 +83,25 @@ pub fn init(callback: js.Function.Temp, options: ?ObserverInit, page: *Page) !*I
         .array => |arr| try arena.dupe(f64, arr),
     };
 
+    const root: ?*Element = blk: {
+        const root_opt = opts.root orelse break :blk null;
+        switch (root_opt._type) {
+            .element => |el| break :blk el,
+            .document => {
+                // not strictly correct, `null` means the viewport, not the
+                // entire document, but since we don't render anything, this
+                // should be fine.
+                break :blk null;
+            },
+            else => return error.TypeError,
+        }
+    };
+
     const self = try arena.create(IntersectionObserver);
     self.* = .{
         ._arena = arena,
         ._callback = callback,
-        ._root = opts.root,
+        ._root = root,
         ._root_margin = root_margin,
         ._threshold = threshold,
     };

src/browser/webapi/ResizeObserver.zig

@@ -62,5 +62,6 @@ pub const JsApi = struct {
 
     pub const constructor = bridge.constructor(ResizeObserver.init, .{});
     pub const observe = bridge.function(ResizeObserver.observe, .{});
+    pub const unobserve = bridge.function(ResizeObserver.unobserve, .{});
     pub const disconnect = bridge.function(ResizeObserver.disconnect, .{});
 };

src/browser/webapi/Window.zig

@@ -49,6 +49,10 @@ const IS_DEBUG = builtin.mode == .Debug;
 
 const Allocator = std.mem.Allocator;
 
+pub fn registerTypes() []const type {
+    return &.{ Window, CrossOriginWindow };
+}
+
 const Window = @This();
 
 _proto: *EventTarget,
@@ -87,6 +91,8 @@ _scroll_pos: struct {
     .y = 0,
     .state = .done,
 },
+// A cross origin wrapper for this window
+_cross_origin_wrapper: CrossOriginWindow,
 
 pub fn asEventTarget(self: *Window) *EventTarget {
     return self._proto;
@@ -104,19 +110,19 @@ pub fn getWindow(self: *Window) *Window {
     return self;
 }
 
-pub fn getTop(self: *Window) *Window {
+pub fn getTop(self: *Window, page: *Page) Access {
     var p = self._page;
     while (p.parent) |parent| {
         p = parent;
     }
-    return p.window;
+    return Access.init(page.window, p.window);
 }
 
-pub fn getParent(self: *Window) *Window {
+pub fn getParent(self: *Window, page: *Page) Access {
     if (self._page.parent) |p| {
-        return p.window;
+        return Access.init(page.window, p.window);
     }
-    return self;
+    return .{ .window = self };
 }
 
 pub fn getDocument(self: *Window) *Document {
@@ -606,6 +612,25 @@ pub fn unhandledPromiseRejection(self: *Window, no_handler: bool, rejection: js.
     }
 }
 
+pub const Access = union(enum) {
+    window: *Window,
+    cross_origin: *CrossOriginWindow,
+
+    pub fn init(callee: *Window, accessing: *Window) Access {
+        if (callee == accessing) {
+            // common enough that it's worth the check
+            return .{ .window = accessing };
+        }
+
+        if (callee._page.js.origin == accessing._page.js.origin) {
+            // two different windows, but same origin, return the full window
+            return .{ .window = accessing };
+        }
+
+        return .{ .cross_origin = &accessing._cross_origin_wrapper };
+    }
+};
+
 const ScheduleOpts = struct {
     repeat: bool,
     params: []js.Value.Temp,
@@ -804,7 +829,7 @@ pub const JsApi = struct {
         pub var class_id: bridge.ClassId = undefined;
     };
 
-    pub const document = bridge.accessor(Window.getDocument, null, .{ .cache = .{ .internal = 1 } });
+    pub const document = bridge.accessor(Window.getDocument, null, .{ .cache = .{ .internal = 1 }, .deletable = false });
     pub const console = bridge.accessor(Window.getConsole, null, .{ .cache = .{ .internal = 2 } });
 
     pub const top = bridge.accessor(Window.getTop, null, .{});
@@ -817,7 +842,7 @@ pub const JsApi = struct {
     pub const performance = bridge.accessor(Window.getPerformance, null, .{});
     pub const localStorage = bridge.accessor(Window.getLocalStorage, null, .{});
     pub const sessionStorage = bridge.accessor(Window.getSessionStorage, null, .{});
-    pub const location = bridge.accessor(Window.getLocation, Window.setLocation, .{});
+    pub const location = bridge.accessor(Window.getLocation, Window.setLocation, .{ .deletable = false });
     pub const history = bridge.accessor(Window.getHistory, null, .{});
     pub const navigation = bridge.accessor(Window.getNavigation, null, .{});
     pub const crypto = bridge.accessor(Window.getCrypto, null, .{});
@@ -892,6 +917,41 @@ pub const JsApi = struct {
     }.prompt, .{});
 };
 
+const CrossOriginWindow = struct {
+    window: *Window,
+
+    pub fn postMessage(self: *CrossOriginWindow, message: js.Value.Temp, target_origin: ?[]const u8, page: *Page) !void {
+        return self.window.postMessage(message, target_origin, page);
+    }
+
+    pub fn getTop(self: *CrossOriginWindow, page: *Page) Access {
+        return self.window.getParent(page);
+    }
+
+    pub fn getParent(self: *CrossOriginWindow, page: *Page) Access {
+        return self.window.getParent(page);
+    }
+
+    pub fn getFramesLength(self: *const CrossOriginWindow) u32 {
+        return self.window.getFramesLength();
+    }
+
+    pub const JsApi = struct {
+        pub const bridge = js.Bridge(CrossOriginWindow);
+
+        pub const Meta = struct {
+            pub const name = "CrossOriginWindow";
+            pub const prototype_chain = bridge.prototypeChain();
+            pub var class_id: bridge.ClassId = undefined;
+        };
+
+        pub const postMessage = bridge.function(CrossOriginWindow.postMessage, .{});
+        pub const top = bridge.accessor(CrossOriginWindow.getTop, null, .{});
+        pub const parent = bridge.accessor(CrossOriginWindow.getParent, null, .{});
+        pub const length = bridge.accessor(CrossOriginWindow.getFramesLength, null, .{});
+    };
+};
+
 const testing = @import("../../testing.zig");
 test "WebApi: Window" {
     try testing.htmlRunner("window", .{});

src/browser/webapi/canvas/CanvasRenderingContext2D.zig

@@ -23,16 +23,24 @@ const js = @import("../../js/js.zig");
 const color = @import("../../color.zig");
 const Page = @import("../../Page.zig");
 
+const Canvas = @import("../element/html/Canvas.zig");
 const ImageData = @import("../ImageData.zig");
 
 /// This class doesn't implement a `constructor`.
 /// It can be obtained with a call to `HTMLCanvasElement#getContext`.
 /// https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D
 const CanvasRenderingContext2D = @This();
+/// Reference to the parent canvas element.
+/// https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/canvas
+_canvas: *Canvas,
 /// Fill color.
 /// TODO: Add support for `CanvasGradient` and `CanvasPattern`.
 _fill_style: color.RGBA = color.RGBA.Named.black,
 
+pub fn getCanvas(self: *const CanvasRenderingContext2D) *Canvas {
+    return self._canvas;
+}
+
 pub fn getFillStyle(self: *const CanvasRenderingContext2D, page: *Page) ![]const u8 {
     var w = std.Io.Writer.Allocating.init(page.call_arena);
     try self._fill_style.format(&w.writer);
@@ -125,6 +133,7 @@ pub const JsApi = struct {
         pub var class_id: bridge.ClassId = undefined;
     };
 
+    pub const canvas = bridge.accessor(CanvasRenderingContext2D.getCanvas, null, .{});
     pub const font = bridge.property("10px sans-serif", .{ .template = false, .readonly = false });
     pub const globalAlpha = bridge.property(1.0, .{ .template = false, .readonly = false });
     pub const globalCompositeOperation = bridge.property("source-over", .{ .template = false, .readonly = false });

src/browser/webapi/element/html/Canvas.zig

@@ -67,9 +67,9 @@ const DrawingContext = union(enum) {
     webgl: *WebGLRenderingContext,
 };
 
-pub fn getContext(_: *Canvas, context_type: []const u8, page: *Page) !?DrawingContext {
+pub fn getContext(self: *Canvas, context_type: []const u8, page: *Page) !?DrawingContext {
     if (std.mem.eql(u8, context_type, "2d")) {
-        const ctx = try page._factory.create(CanvasRenderingContext2D{});
+        const ctx = try page._factory.create(CanvasRenderingContext2D{ ._canvas = self });
         return .{ .@"2d" = ctx };
     }
 

src/browser/webapi/element/html/IFrame.zig

@@ -39,8 +39,9 @@ pub fn asNode(self: *IFrame) *Node {
     return self.asElement().asNode();
 }
 
-pub fn getContentWindow(self: *const IFrame) ?*Window {
-    return self._window;
+pub fn getContentWindow(self: *const IFrame, page: *Page) ?Window.Access {
+    const frame_window = self._window orelse return null;
+    return Window.Access.init(page.window, frame_window);
 }
 
 pub fn getContentDocument(self: *const IFrame) ?*Document {

src/browser/webapi/event/FormDataEvent.zig

@@ -0,0 +1,95 @@
+// Copyright (C) 2023-2026 Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const String = @import("../../../string.zig").String;
+const Page = @import("../../Page.zig");
+const Session = @import("../../Session.zig");
+const js = @import("../../js/js.zig");
+
+const Event = @import("../Event.zig");
+const UIEvent = @import("UIEvent.zig");
+
+const FormData = @import("../net/FormData.zig");
+
+/// https://developer.mozilla.org/en-US/docs/Web/API/FormDataEvent
+const FormDataEvent = @This();
+
+_proto: *Event,
+_form_data: ?*FormData = null,
+
+const Options = Event.inheritOptions(FormDataEvent, struct {
+    formData: ?*FormData = null,
+});
+
+pub fn init(typ: []const u8, maybe_options: Options, page: *Page) !*FormDataEvent {
+    const arena = try page.getArena(.{ .debug = "FormDataEvent" });
+    errdefer page.releaseArena(arena);
+    const type_string = try String.init(arena, typ, .{});
+    return initWithTrusted(arena, type_string, maybe_options, false, page);
+}
+
+pub fn initTrusted(typ: String, _opts: ?Options, page: *Page) !*FormDataEvent {
+    const arena = try page.getArena(.{ .debug = "FormDataEvent.trusted" });
+    errdefer page.releaseArena(arena);
+    return initWithTrusted(arena, typ, _opts, true, page);
+}
+
+fn initWithTrusted(arena: Allocator, typ: String, maybe_options: ?Options, trusted: bool, page: *Page) !*FormDataEvent {
+    const options = maybe_options orelse Options{};
+
+    const event = try page._factory.event(
+        arena,
+        typ,
+        FormDataEvent{
+            ._proto = undefined,
+            ._form_data = options.formData,
+        },
+    );
+
+    Event.populatePrototypes(event, options, trusted);
+    return event;
+}
+
+pub fn deinit(self: *FormDataEvent, shutdown: bool, session: *Session) void {
+    self._proto.deinit(shutdown, session);
+}
+
+pub fn asEvent(self: *FormDataEvent) *Event {
+    return self._proto;
+}
+
+pub fn getFormData(self: *const FormDataEvent) ?*FormData {
+    return self._form_data;
+}
+
+pub const JsApi = struct {
+    pub const bridge = js.Bridge(FormDataEvent);
+
+    pub const Meta = struct {
+        pub const name = "FormDataEvent";
+        pub const prototype_chain = bridge.prototypeChain();
+        pub var class_id: bridge.ClassId = undefined;
+        pub const weak = true;
+        pub const finalizer = bridge.finalizer(FormDataEvent.deinit);
+    };
+
+    pub const constructor = bridge.constructor(FormDataEvent.init, .{});
+    pub const formData = bridge.accessor(FormDataEvent.getFormData, null, .{});
+};

src/browser/webapi/event/SubmitEvent.zig

@@ -26,7 +26,7 @@ const Event = @import("../Event.zig");
 const HtmlElement = @import("../element/Html.zig");
 const Allocator = std.mem.Allocator;
 
-// https://developer.mozilla.org/en-US/docs/Web/API/SubmitEvent
+/// https://developer.mozilla.org/en-US/docs/Web/API/SubmitEvent
 const SubmitEvent = @This();
 
 _proto: *Event,

src/browser/webapi/net/FormData.zig

@@ -35,10 +35,22 @@ _arena: Allocator,
 _list: KeyValueList,
 
 pub fn init(form: ?*Form, submitter: ?*Element, page: *Page) !*FormData {
-    return page._factory.create(FormData{
+    const form_data = try page._factory.create(FormData{
         ._arena = page.arena,
         ._list = try collectForm(page.arena, form, submitter, page),
     });
+
+    // Dispatch `formdata` event if form provided.
+    if (form) |_form| {
+        const form_data_event = try (@import("../event/FormDataEvent.zig")).initTrusted(
+            comptime .wrap("formdata"),
+            .{ .bubbles = true, .cancelable = false, .formData = form_data },
+            page,
+        );
+        try page._event_manager.dispatch(_form.asNode().asEventTarget(), form_data_event.asEvent());
+    }
+
+    return form_data;
 }
 
 pub fn get(self: *const FormData, name: []const u8) ?[]const u8 {

src/cdp/CDP.zig

@@ -22,297 +22,294 @@ const lp = @import("lightpanda");
 const Allocator = std.mem.Allocator;
 const json = std.json;
 
-const log = @import("../log.zig");
-const js = @import("../browser/js/js.zig");
+const Incrementing = @import("id.zig").Incrementing;
 
+const log = @import("../log.zig");
 const App = @import("../App.zig");
+const Notification = @import("../Notification.zig");
+
+const Client = @import("../Server.zig").Client;
+
+const js = @import("../browser/js/js.zig");
 const Browser = @import("../browser/Browser.zig");
 const Session = @import("../browser/Session.zig");
-const HttpClient = @import("../browser/HttpClient.zig");
 const Page = @import("../browser/Page.zig");
-const Incrementing = @import("id.zig").Incrementing;
-const Notification = @import("../Notification.zig");
-const InterceptState = @import("domains/fetch.zig").InterceptState;
 const Mime = @import("../browser/Mime.zig");
+const HttpClient = @import("../browser/HttpClient.zig");
+
+const InterceptState = @import("domains/fetch.zig").InterceptState;
 
 pub const URL_BASE = "chrome://newtab/";
 
 const IS_DEBUG = @import("builtin").mode == .Debug;
 
-pub const CDP = CDPT(struct {
-    const Client = *@import("../Server.zig").Client;
-});
-
-const SessionIdGen = Incrementing(u32, "SID");
 const TargetIdGen = Incrementing(u32, "TID");
+const SessionIdGen = Incrementing(u32, "SID");
 const BrowserContextIdGen = Incrementing(u32, "BID");
 
 // Generic so that we can inject mocks into it.
-pub fn CDPT(comptime TypeProvider: type) type {
-    return struct {
-        // Used for sending message to the client and closing on error
-        client: TypeProvider.Client,
+const CDP = @This();
 
-        allocator: Allocator,
+// Used for sending message to the client and closing on error
+client: *Client,
 
-        // The active browser
-        browser: Browser,
+allocator: Allocator,
 
-        // when true, any target creation must be attached.
-        target_auto_attach: bool = false,
+// The active browser
+browser: Browser,
 
-        target_id_gen: TargetIdGen = .{},
-        session_id_gen: SessionIdGen = .{},
-        browser_context_id_gen: BrowserContextIdGen = .{},
+// when true, any target creation must be attached.
+target_auto_attach: bool = false,
 
-        browser_context: ?BrowserContext(Self),
+target_id_gen: TargetIdGen = .{},
+session_id_gen: SessionIdGen = .{},
+browser_context_id_gen: BrowserContextIdGen = .{},
 
-        // Re-used arena for processing a message. We're assuming that we're getting
-        // 1 message at a time.
-        message_arena: std.heap.ArenaAllocator,
+browser_context: ?BrowserContext(CDP),
 
-        // Used for processing notifications within a browser context.
-        notification_arena: std.heap.ArenaAllocator,
+// Re-used arena for processing a message. We're assuming that we're getting
+// 1 message at a time.
+message_arena: std.heap.ArenaAllocator,
 
-        // Valid for 1 page navigation (what CDP calls a "renderer")
-        page_arena: std.heap.ArenaAllocator,
+// Used for processing notifications within a browser context.
+notification_arena: std.heap.ArenaAllocator,
 
-        // Valid for the entire lifetime of the BrowserContext. Should minimize
-        // (or altogether elimiate) our use of this.
-        browser_context_arena: std.heap.ArenaAllocator,
+// Valid for 1 page navigation (what CDP calls a "renderer")
+page_arena: std.heap.ArenaAllocator,
 
-        const Self = @This();
+// Valid for the entire lifetime of the BrowserContext. Should minimize
+// (or altogether elimiate) our use of this.
+browser_context_arena: std.heap.ArenaAllocator,
 
-        pub fn init(app: *App, http_client: *HttpClient, client: TypeProvider.Client) !Self {
-            const allocator = app.allocator;
-            const browser = try Browser.init(app, .{
-                .env = .{ .with_inspector = true },
-                .http_client = http_client,
-            });
-            errdefer browser.deinit();
+pub fn init(client: *Client) !CDP {
+    const app = client.app;
+    const allocator = app.allocator;
+    const browser = try Browser.init(app, .{
+        .env = .{ .with_inspector = true },
+        .http_client = client.http,
+    });
+    errdefer browser.deinit();
 
-            return .{
-                .client = client,
-                .browser = browser,
-                .allocator = allocator,
-                .browser_context = null,
-                .page_arena = std.heap.ArenaAllocator.init(allocator),
-                .message_arena = std.heap.ArenaAllocator.init(allocator),
-                .notification_arena = std.heap.ArenaAllocator.init(allocator),
-                .browser_context_arena = std.heap.ArenaAllocator.init(allocator),
-            };
-        }
-
-        pub fn deinit(self: *Self) void {
-            if (self.browser_context) |*bc| {
-                bc.deinit();
-            }
-            self.browser.deinit();
-            self.page_arena.deinit();
-            self.message_arena.deinit();
-            self.notification_arena.deinit();
-            self.browser_context_arena.deinit();
-        }
-
-        pub fn handleMessage(self: *Self, msg: []const u8) bool {
-            // if there's an error, it's already been logged
-            self.processMessage(msg) catch return false;
-            return true;
-        }
-
-        pub fn processMessage(self: *Self, msg: []const u8) !void {
-            const arena = &self.message_arena;
-            defer _ = arena.reset(.{ .retain_with_limit = 1024 * 16 });
-            return self.dispatch(arena.allocator(), self, msg);
-        }
-
-        // @newhttp
-        // A bit hacky right now. The main server loop doesn't unblock for
-        // scheduled task. So we run this directly in order to process any
-        // timeouts (or http events) which are ready to be processed.
-        pub fn pageWait(self: *Self, ms: u32) !Session.Runner.CDPWaitResult {
-            const session = &(self.browser.session orelse return error.NoPage);
-            var runner = try session.runner(.{});
-            return runner.waitCDP(.{ .ms = ms });
-        }
-
-        // Called from above, in processMessage which handles client messages
-        // but can also be called internally. For example, Target.sendMessageToTarget
-        // calls back into dispatch to capture the response.
-        pub fn dispatch(self: *Self, arena: Allocator, sender: anytype, str: []const u8) !void {
-            const input = json.parseFromSliceLeaky(InputMessage, arena, str, .{
-                .ignore_unknown_fields = true,
-            }) catch return error.InvalidJSON;
-
-            var command = Command(Self, @TypeOf(sender)){
-                .input = .{
-                    .json = str,
-                    .id = input.id,
-                    .action = "",
-                    .params = input.params,
-                    .session_id = input.sessionId,
-                },
-                .cdp = self,
-                .arena = arena,
-                .sender = sender,
-                .browser_context = if (self.browser_context) |*bc| bc else null,
-            };
-
-            // See dispatchStartupCommand for more info on this.
-            var is_startup = false;
-            if (input.sessionId) |input_session_id| {
-                if (std.mem.eql(u8, input_session_id, "STARTUP")) {
-                    is_startup = true;
-                } else if (self.isValidSessionId(input_session_id) == false) {
-                    return command.sendError(-32001, "Unknown sessionId", .{});
-                }
-            }
-
-            if (is_startup) {
-                dispatchStartupCommand(&command, input.method) catch |err| {
-                    command.sendError(-31999, @errorName(err), .{}) catch return err;
-                };
-            } else {
-                dispatchCommand(&command, input.method) catch |err| {
-                    command.sendError(-31998, @errorName(err), .{}) catch return err;
-                };
-            }
-        }
-
-        // A CDP session isn't 100% fully driven by the driver. There's are
-        // independent actions that the browser is expected to take. For example
-        // Puppeteer expects the browser to startup a tab and thus have existing
-        // targets.
-        // To this end, we create a [very] dummy BrowserContext, Target and
-        // Session. There isn't actually a BrowserContext, just a special id.
-        // When messages are received with the "STARTUP" sessionId, we do
-        // "special" handling - the bare minimum we need to do until the driver
-        // switches to a real BrowserContext.
-        // (I can imagine this logic will become driver-specific)
-        fn dispatchStartupCommand(command: anytype, method: []const u8) !void {
-            // Stagehand parses the response and error if we don't return a
-            // correct one for Page.getFrameTree on startup call.
-            if (std.mem.eql(u8, method, "Page.getFrameTree")) {
-                // The Page.getFrameTree handles startup response gracefully.
-                return dispatchCommand(command, method);
-            }
-
-            return command.sendResult(null, .{});
-        }
-
-        fn dispatchCommand(command: anytype, method: []const u8) !void {
-            const domain = blk: {
-                const i = std.mem.indexOfScalarPos(u8, method, 0, '.') orelse {
-                    return error.InvalidMethod;
-                };
-                command.input.action = method[i + 1 ..];
-                break :blk method[0..i];
-            };
-
-            switch (domain.len) {
-                2 => switch (@as(u16, @bitCast(domain[0..2].*))) {
-                    asUint(u16, "LP") => return @import("domains/lp.zig").processMessage(command),
-                    else => {},
-                },
-                3 => switch (@as(u24, @bitCast(domain[0..3].*))) {
-                    asUint(u24, "DOM") => return @import("domains/dom.zig").processMessage(command),
-                    asUint(u24, "Log") => return @import("domains/log.zig").processMessage(command),
-                    asUint(u24, "CSS") => return @import("domains/css.zig").processMessage(command),
-                    else => {},
-                },
-                4 => switch (@as(u32, @bitCast(domain[0..4].*))) {
-                    asUint(u32, "Page") => return @import("domains/page.zig").processMessage(command),
-                    else => {},
-                },
-                5 => switch (@as(u40, @bitCast(domain[0..5].*))) {
-                    asUint(u40, "Fetch") => return @import("domains/fetch.zig").processMessage(command),
-                    asUint(u40, "Input") => return @import("domains/input.zig").processMessage(command),
-                    else => {},
-                },
-                6 => switch (@as(u48, @bitCast(domain[0..6].*))) {
-                    asUint(u48, "Target") => return @import("domains/target.zig").processMessage(command),
-                    else => {},
-                },
-                7 => switch (@as(u56, @bitCast(domain[0..7].*))) {
-                    asUint(u56, "Browser") => return @import("domains/browser.zig").processMessage(command),
-                    asUint(u56, "Runtime") => return @import("domains/runtime.zig").processMessage(command),
-                    asUint(u56, "Network") => return @import("domains/network.zig").processMessage(command),
-                    asUint(u56, "Storage") => return @import("domains/storage.zig").processMessage(command),
-                    else => {},
-                },
-                8 => switch (@as(u64, @bitCast(domain[0..8].*))) {
-                    asUint(u64, "Security") => return @import("domains/security.zig").processMessage(command),
-                    else => {},
-                },
-                9 => switch (@as(u72, @bitCast(domain[0..9].*))) {
-                    asUint(u72, "Emulation") => return @import("domains/emulation.zig").processMessage(command),
-                    asUint(u72, "Inspector") => return @import("domains/inspector.zig").processMessage(command),
-                    else => {},
-                },
-                11 => switch (@as(u88, @bitCast(domain[0..11].*))) {
-                    asUint(u88, "Performance") => return @import("domains/performance.zig").processMessage(command),
-                    else => {},
-                },
-                13 => switch (@as(u104, @bitCast(domain[0..13].*))) {
-                    asUint(u104, "Accessibility") => return @import("domains/accessibility.zig").processMessage(command),
-                    else => {},
-                },
-
-                else => {},
-            }
-
-            return error.UnknownDomain;
-        }
-
-        fn isValidSessionId(self: *const Self, input_session_id: []const u8) bool {
-            const browser_context = &(self.browser_context orelse return false);
-            const session_id = browser_context.session_id orelse return false;
-            return std.mem.eql(u8, session_id, input_session_id);
-        }
-
-        pub fn createBrowserContext(self: *Self) ![]const u8 {
-            if (self.browser_context != null) {
-                return error.AlreadyExists;
-            }
-            const id = self.browser_context_id_gen.next();
-
-            self.browser_context = @as(BrowserContext(Self), undefined);
-            const browser_context = &self.browser_context.?;
-
-            try BrowserContext(Self).init(browser_context, id, self);
-            return id;
-        }
-
-        pub fn disposeBrowserContext(self: *Self, browser_context_id: []const u8) bool {
-            const bc = &(self.browser_context orelse return false);
-            if (std.mem.eql(u8, bc.id, browser_context_id) == false) {
-                return false;
-            }
-            bc.deinit();
-            self.browser.closeSession();
-            self.browser_context = null;
-            return true;
-        }
-
-        const SendEventOpts = struct {
-            session_id: ?[]const u8 = null,
-        };
-        pub fn sendEvent(self: *Self, method: []const u8, p: anytype, opts: SendEventOpts) !void {
-            return self.sendJSON(.{
-                .method = method,
-                .params = if (comptime @typeInfo(@TypeOf(p)) == .null) struct {}{} else p,
-                .sessionId = opts.session_id,
-            });
-        }
-
-        pub fn sendJSON(self: *Self, message: anytype) !void {
-            return self.client.sendJSON(message, .{
-                .emit_null_optional_fields = false,
-            });
-        }
+    return .{
+        .client = client,
+        .browser = browser,
+        .allocator = allocator,
+        .browser_context = null,
+        .page_arena = std.heap.ArenaAllocator.init(allocator),
+        .message_arena = std.heap.ArenaAllocator.init(allocator),
+        .notification_arena = std.heap.ArenaAllocator.init(allocator),
+        .browser_context_arena = std.heap.ArenaAllocator.init(allocator),
     };
 }
 
+pub fn deinit(self: *CDP) void {
+    if (self.browser_context) |*bc| {
+        bc.deinit();
+    }
+    self.browser.deinit();
+    self.page_arena.deinit();
+    self.message_arena.deinit();
+    self.notification_arena.deinit();
+    self.browser_context_arena.deinit();
+}
+
+pub fn handleMessage(self: *CDP, msg: []const u8) bool {
+    // if there's an error, it's already been logged
+    self.processMessage(msg) catch return false;
+    return true;
+}
+
+pub fn processMessage(self: *CDP, msg: []const u8) !void {
+    const arena = &self.message_arena;
+    defer _ = arena.reset(.{ .retain_with_limit = 1024 * 16 });
+    return self.dispatch(arena.allocator(), self, msg);
+}
+
+// @newhttp
+// A bit hacky right now. The main server loop doesn't unblock for
+// scheduled task. So we run this directly in order to process any
+// timeouts (or http events) which are ready to be processed.
+pub fn pageWait(self: *CDP, ms: u32) !Session.Runner.CDPWaitResult {
+    const session = &(self.browser.session orelse return error.NoPage);
+    var runner = try session.runner(.{});
+    return runner.waitCDP(.{ .ms = ms });
+}
+
+// Called from above, in processMessage which handles client messages
+// but can also be called internally. For example, Target.sendMessageToTarget
+// calls back into dispatch to capture the response.
+pub fn dispatch(self: *CDP, arena: Allocator, sender: anytype, str: []const u8) !void {
+    const input = json.parseFromSliceLeaky(InputMessage, arena, str, .{
+        .ignore_unknown_fields = true,
+    }) catch return error.InvalidJSON;
+
+    var command = Command(CDP, @TypeOf(sender)){
+        .input = .{
+            .json = str,
+            .id = input.id,
+            .action = "",
+            .params = input.params,
+            .session_id = input.sessionId,
+        },
+        .cdp = self,
+        .arena = arena,
+        .sender = sender,
+        .browser_context = if (self.browser_context) |*bc| bc else null,
+    };
+
+    // See dispatchStartupCommand for more info on this.
+    var is_startup = false;
+    if (input.sessionId) |input_session_id| {
+        if (std.mem.eql(u8, input_session_id, "STARTUP")) {
+            is_startup = true;
+        } else if (self.isValidSessionId(input_session_id) == false) {
+            return command.sendError(-32001, "Unknown sessionId", .{});
+        }
+    }
+
+    if (is_startup) {
+        dispatchStartupCommand(&command, input.method) catch |err| {
+            command.sendError(-31999, @errorName(err), .{}) catch return err;
+        };
+    } else {
+        dispatchCommand(&command, input.method) catch |err| {
+            command.sendError(-31998, @errorName(err), .{}) catch return err;
+        };
+    }
+}
+
+// A CDP session isn't 100% fully driven by the driver. There's are
+// independent actions that the browser is expected to take. For example
+// Puppeteer expects the browser to startup a tab and thus have existing
+// targets.
+// To this end, we create a [very] dummy BrowserContext, Target and
+// Session. There isn't actually a BrowserContext, just a special id.
+// When messages are received with the "STARTUP" sessionId, we do
+// "special" handling - the bare minimum we need to do until the driver
+// switches to a real BrowserContext.
+// (I can imagine this logic will become driver-specific)
+fn dispatchStartupCommand(command: anytype, method: []const u8) !void {
+    // Stagehand parses the response and error if we don't return a
+    // correct one for Page.getFrameTree on startup call.
+    if (std.mem.eql(u8, method, "Page.getFrameTree")) {
+        // The Page.getFrameTree handles startup response gracefully.
+        return dispatchCommand(command, method);
+    }
+
+    return command.sendResult(null, .{});
+}
+
+fn dispatchCommand(command: anytype, method: []const u8) !void {
+    const domain = blk: {
+        const i = std.mem.indexOfScalarPos(u8, method, 0, '.') orelse {
+            return error.InvalidMethod;
+        };
+        command.input.action = method[i + 1 ..];
+        break :blk method[0..i];
+    };
+
+    switch (domain.len) {
+        2 => switch (@as(u16, @bitCast(domain[0..2].*))) {
+            asUint(u16, "LP") => return @import("domains/lp.zig").processMessage(command),
+            else => {},
+        },
+        3 => switch (@as(u24, @bitCast(domain[0..3].*))) {
+            asUint(u24, "DOM") => return @import("domains/dom.zig").processMessage(command),
+            asUint(u24, "Log") => return @import("domains/log.zig").processMessage(command),
+            asUint(u24, "CSS") => return @import("domains/css.zig").processMessage(command),
+            else => {},
+        },
+        4 => switch (@as(u32, @bitCast(domain[0..4].*))) {
+            asUint(u32, "Page") => return @import("domains/page.zig").processMessage(command),
+            else => {},
+        },
+        5 => switch (@as(u40, @bitCast(domain[0..5].*))) {
+            asUint(u40, "Fetch") => return @import("domains/fetch.zig").processMessage(command),
+            asUint(u40, "Input") => return @import("domains/input.zig").processMessage(command),
+            else => {},
+        },
+        6 => switch (@as(u48, @bitCast(domain[0..6].*))) {
+            asUint(u48, "Target") => return @import("domains/target.zig").processMessage(command),
+            else => {},
+        },
+        7 => switch (@as(u56, @bitCast(domain[0..7].*))) {
+            asUint(u56, "Browser") => return @import("domains/browser.zig").processMessage(command),
+            asUint(u56, "Runtime") => return @import("domains/runtime.zig").processMessage(command),
+            asUint(u56, "Network") => return @import("domains/network.zig").processMessage(command),
+            asUint(u56, "Storage") => return @import("domains/storage.zig").processMessage(command),
+            else => {},
+        },
+        8 => switch (@as(u64, @bitCast(domain[0..8].*))) {
+            asUint(u64, "Security") => return @import("domains/security.zig").processMessage(command),
+            else => {},
+        },
+        9 => switch (@as(u72, @bitCast(domain[0..9].*))) {
+            asUint(u72, "Emulation") => return @import("domains/emulation.zig").processMessage(command),
+            asUint(u72, "Inspector") => return @import("domains/inspector.zig").processMessage(command),
+            else => {},
+        },
+        11 => switch (@as(u88, @bitCast(domain[0..11].*))) {
+            asUint(u88, "Performance") => return @import("domains/performance.zig").processMessage(command),
+            else => {},
+        },
+        13 => switch (@as(u104, @bitCast(domain[0..13].*))) {
+            asUint(u104, "Accessibility") => return @import("domains/accessibility.zig").processMessage(command),
+            else => {},
+        },
+
+        else => {},
+    }
+
+    return error.UnknownDomain;
+}
+
+fn isValidSessionId(self: *const CDP, input_session_id: []const u8) bool {
+    const browser_context = &(self.browser_context orelse return false);
+    const session_id = browser_context.session_id orelse return false;
+    return std.mem.eql(u8, session_id, input_session_id);
+}
+
+pub fn createBrowserContext(self: *CDP) ![]const u8 {
+    if (self.browser_context != null) {
+        return error.AlreadyExists;
+    }
+    const id = self.browser_context_id_gen.next();
+
+    self.browser_context = @as(BrowserContext(CDP), undefined);
+    const browser_context = &self.browser_context.?;
+
+    try BrowserContext(CDP).init(browser_context, id, self);
+    return id;
+}
+
+pub fn disposeBrowserContext(self: *CDP, browser_context_id: []const u8) bool {
+    const bc = &(self.browser_context orelse return false);
+    if (std.mem.eql(u8, bc.id, browser_context_id) == false) {
+        return false;
+    }
+    bc.deinit();
+    self.browser.closeSession();
+    self.browser_context = null;
+    return true;
+}
+
+const SendEventOpts = struct {
+    session_id: ?[]const u8 = null,
+};
+pub fn sendEvent(self: *CDP, method: []const u8, p: anytype, opts: SendEventOpts) !void {
+    return self.sendJSON(.{
+        .method = method,
+        .params = if (comptime @typeInfo(@TypeOf(p)) == .null) struct {}{} else p,
+        .sessionId = opts.session_id,
+    });
+}
+
+pub fn sendJSON(self: *CDP, message: anytype) !void {
+    return self.client.sendJSON(message, .{
+        .emit_null_optional_fields = false,
+    });
+}
+
 pub fn BrowserContext(comptime CDP_T: type) type {
     const Node = @import("Node.zig");
     const AXNode = @import("AXNode.zig");
@@ -958,7 +955,7 @@ fn asUint(comptime T: type, comptime string: []const u8) T {
 
 const testing = @import("testing.zig");
 test "cdp: invalid json" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     try testing.expectError(error.InvalidJSON, ctx.processMessage("invalid"));
@@ -983,7 +980,7 @@ test "cdp: invalid json" {
 }
 
 test "cdp: invalid sessionId" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -1008,7 +1005,7 @@ test "cdp: invalid sessionId" {
 }
 
 test "cdp: STARTUP sessionId" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -1021,13 +1018,13 @@ test "cdp: STARTUP sessionId" {
         // we have a brower context but no session_id
         _ = try ctx.loadBrowserContext(.{});
         try ctx.processMessage(.{ .id = 3, .method = "Hi", .sessionId = "STARTUP" });
-        try ctx.expectSentResult(null, .{ .id = 3, .index = 0, .session_id = "STARTUP" });
+        try ctx.expectSentResult(null, .{ .id = 3, .index = 1, .session_id = "STARTUP" });
     }
 
     {
         // we have a brower context with a different session_id
         _ = try ctx.loadBrowserContext(.{ .session_id = "SESS-2" });
         try ctx.processMessage(.{ .id = 4, .method = "Hi", .sessionId = "STARTUP" });
-        try ctx.expectSentResult(null, .{ .id = 4, .index = 0, .session_id = "STARTUP" });
+        try ctx.expectSentResult(null, .{ .id = 4, .index = 2, .session_id = "STARTUP" });
     }
 }

src/cdp/domains/browser.zig

@@ -112,7 +112,7 @@ fn resetPermissions(cmd: anytype) !void {
 
 const testing = @import("../testing.zig");
 test "cdp.browser: getVersion" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     try ctx.processMessage(.{
@@ -131,7 +131,7 @@ test "cdp.browser: getVersion" {
 }
 
 test "cdp.browser: getWindowForTarget" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     try ctx.processMessage(.{

src/cdp/domains/dom.zig

@@ -547,7 +547,7 @@ fn requestNode(cmd: anytype) !void {
 
 const testing = @import("../testing.zig");
 test "cdp.dom: getSearchResults unknown search id" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     try ctx.processMessage(.{
@@ -559,7 +559,7 @@ test "cdp.dom: getSearchResults unknown search id" {
 }
 
 test "cdp.dom: search flow" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .url = "cdp/dom1.html" });
@@ -614,7 +614,7 @@ test "cdp.dom: search flow" {
 }
 
 test "cdp.dom: querySelector unknown search id" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .url = "cdp/dom1.html" });
@@ -635,7 +635,7 @@ test "cdp.dom: querySelector unknown search id" {
 }
 
 test "cdp.dom: querySelector Node not found" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .url = "cdp/dom1.html" });
@@ -663,7 +663,7 @@ test "cdp.dom: querySelector Node not found" {
 }
 
 test "cdp.dom: querySelector Nodes found" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .url = "cdp/dom2.html" });
@@ -693,7 +693,7 @@ test "cdp.dom: querySelector Nodes found" {
 }
 
 test "cdp.dom: getBoxModel" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .url = "cdp/dom2.html" });

src/cdp/domains/lp.zig

@@ -135,17 +135,10 @@ fn getInteractiveElements(cmd: anytype) !void {
         page.document.asNode();
 
     const elements = try interactive.collectInteractiveElements(root, cmd.arena, page);
-
-    // Register nodes so nodeIds are valid for subsequent CDP calls.
-    var node_ids: std.ArrayList(Node.Id) = try .initCapacity(cmd.arena, elements.len);
-    for (elements) |el| {
-        const registered = try bc.node_registry.register(el.node);
-        node_ids.appendAssumeCapacity(registered.id);
-    }
+    try interactive.registerNodes(elements, &bc.node_registry);
 
     return cmd.sendResult(.{
         .elements = elements,
-        .nodeIds = node_ids.items,
     }, .{});
 }
 
@@ -279,7 +272,7 @@ fn waitForSelector(cmd: anytype) !void {
 
 const testing = @import("../testing.zig");
 test "cdp.lp: getMarkdown" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     const bc = try ctx.loadBrowserContext(.{});
@@ -290,12 +283,12 @@ test "cdp.lp: getMarkdown" {
         .method = "LP.getMarkdown",
     });
 
-    const result = ctx.client.?.sent.items[0].object.get("result").?.object;
+    const result = (try ctx.getSentMessage(0)).?.object.get("result").?.object;
     try testing.expect(result.get("markdown") != null);
 }
 
 test "cdp.lp: getInteractiveElements" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     const bc = try ctx.loadBrowserContext(.{});
@@ -306,13 +299,12 @@ test "cdp.lp: getInteractiveElements" {
         .method = "LP.getInteractiveElements",
     });
 
-    const result = ctx.client.?.sent.items[0].object.get("result").?.object;
+    const result = (try ctx.getSentMessage(0)).?.object.get("result").?.object;
     try testing.expect(result.get("elements") != null);
-    try testing.expect(result.get("nodeIds") != null);
 }
 
 test "cdp.lp: getStructuredData" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     const bc = try ctx.loadBrowserContext(.{});
@@ -323,12 +315,12 @@ test "cdp.lp: getStructuredData" {
         .method = "LP.getStructuredData",
     });
 
-    const result = ctx.client.?.sent.items[0].object.get("result").?.object;
+    const result = (try ctx.getSentMessage(0)).?.object.get("result").?.object;
     try testing.expect(result.get("structuredData") != null);
 }
 
 test "cdp.lp: action tools" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     const bc = try ctx.loadBrowserContext(.{});
@@ -389,7 +381,7 @@ test "cdp.lp: action tools" {
 }
 
 test "cdp.lp: waitForSelector" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     const bc = try ctx.loadBrowserContext(.{});
@@ -405,9 +397,8 @@ test "cdp.lp: waitForSelector" {
         .method = "LP.waitForSelector",
         .params = .{ .selector = "#existing", .timeout = 2000 },
     });
-    var result = ctx.client.?.sent.items[0].object.get("result").?.object;
+    var result = (try ctx.getSentMessage(0)).?.object.get("result").?.object;
     try testing.expect(result.get("backendNodeId") != null);
-    ctx.client.?.sent.clearRetainingCapacity();
 
     // 2. Delayed element
     try ctx.processMessage(.{
@@ -415,9 +406,8 @@ test "cdp.lp: waitForSelector" {
         .method = "LP.waitForSelector",
         .params = .{ .selector = "#delayed", .timeout = 5000 },
     });
-    result = ctx.client.?.sent.items[0].object.get("result").?.object;
+    result = (try ctx.getSentMessage(1)).?.object.get("result").?.object;
     try testing.expect(result.get("backendNodeId") != null);
-    ctx.client.?.sent.clearRetainingCapacity();
 
     // 3. Timeout error
     try ctx.processMessage(.{
@@ -425,6 +415,6 @@ test "cdp.lp: waitForSelector" {
         .method = "LP.waitForSelector",
         .params = .{ .selector = "#nonexistent", .timeout = 100 },
     });
-    const err_obj = ctx.client.?.sent.items[0].object.get("error").?.object;
+    const err_obj = (try ctx.getSentMessage(2)).?.object.get("error").?.object;
     try testing.expect(err_obj.get("code") != null);
 }

src/cdp/domains/network.zig

@@ -439,7 +439,7 @@ fn idFromRequestId(request_id: []const u8) !u64 {
 
 const testing = @import("../testing.zig");
 test "cdp.network setExtraHTTPHeaders" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "NID-A", .session_id = "NESI-A" });
@@ -465,7 +465,7 @@ test "cdp.Network: cookies" {
     const ResCookie = CdpStorage.ResCookie;
     const CdpCookie = CdpStorage.CdpCookie;
 
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     _ = try ctx.loadBrowserContext(.{ .id = "BID-S" });
 

src/cdp/domains/page.zig

@@ -39,6 +39,7 @@ pub fn processMessage(cmd: anytype) !void {
         addScriptToEvaluateOnNewDocument,
         createIsolatedWorld,
         navigate,
+        reload,
         stopLoading,
         close,
         captureScreenshot,
@@ -52,6 +53,7 @@ pub fn processMessage(cmd: anytype) !void {
         .addScriptToEvaluateOnNewDocument => return addScriptToEvaluateOnNewDocument(cmd),
         .createIsolatedWorld => return createIsolatedWorld(cmd),
         .navigate => return navigate(cmd),
+        .reload => return doReload(cmd),
         .stopLoading => return cmd.sendResult(null, .{}),
         .close => return close(cmd),
         .captureScreenshot => return captureScreenshot(cmd),
@@ -82,7 +84,7 @@ fn getFrameTree(cmd: anytype) !void {
             .frame = .{
                 .id = "TID-STARTUP",
                 .loaderId = "LID-STARTUP",
-                .securityOrigin = @import("../cdp.zig").URL_BASE,
+                .securityOrigin = @import("../CDP.zig").URL_BASE,
                 .url = "about:blank",
                 .secureContextType = "Secure",
             },
@@ -252,6 +254,36 @@ fn navigate(cmd: anytype) !void {
     });
 }
 
+fn doReload(cmd: anytype) !void {
+    const params = try cmd.params(struct {
+        ignoreCache: ?bool = null,
+        scriptToEvaluateOnLoad: ?[]const u8 = null,
+    });
+
+    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
+
+    if (bc.session_id == null) {
+        return error.SessionIdNotLoaded;
+    }
+
+    const session = bc.session;
+    var page = session.currentPage() orelse return error.PageNotLoaded;
+
+    // Dupe URL before replacePage() frees the old page's arena.
+    const reload_url = try cmd.arena.dupeZ(u8, page.url);
+
+    if (page._load_state != .waiting) {
+        page = try session.replacePage();
+    }
+
+    try page.navigate(reload_url, .{
+        .reason = .address_bar,
+        .cdp_id = cmd.input.id,
+        .kind = .reload,
+        .force = if (params) |p| p.ignoreCache orelse false else false,
+    });
+}
+
 pub fn pageNavigate(bc: anytype, event: *const Notification.PageNavigate) !void {
     // detachTarget could be called, in which case, we still have a page doing
     // things, but no session.
@@ -642,7 +674,7 @@ fn getLayoutMetrics(cmd: anytype) !void {
 
 const testing = @import("../testing.zig");
 test "cdp.page: getFrameTree" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -712,7 +744,7 @@ test "cdp.page: captureScreenshot" {
     const filter: LogFilter = .init(&.{.not_implemented});
     defer filter.deinit();
 
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     {
         try ctx.processMessage(.{ .id = 10, .method = "Page.captureScreenshot", .params = .{ .format = "jpg" } });
@@ -728,7 +760,7 @@ test "cdp.page: captureScreenshot" {
 }
 
 test "cdp.page: getLayoutMetrics" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-9", .url = "hi.html", .target_id = "FID-000000000X".* });
@@ -784,3 +816,27 @@ test "cdp.page: getLayoutMetrics" {
         },
     }, .{ .id = 12 });
 }
+
+test "cdp.page: reload" {
+    var ctx = try testing.context();
+    defer ctx.deinit();
+
+    {
+        // reload without browser context — should error
+        try ctx.processMessage(.{ .id = 30, .method = "Page.reload" });
+        try ctx.expectSentError(-31998, "BrowserContextNotLoaded", .{ .id = 30 });
+    }
+
+    _ = try ctx.loadBrowserContext(.{ .id = "BID-9", .url = "hi.html", .target_id = "FID-000000000X".* });
+
+    {
+        // reload with no params — should not error (navigation is async,
+        // so no result is sent synchronously; we just verify no error)
+        try ctx.processMessage(.{ .id = 31, .method = "Page.reload" });
+    }
+
+    {
+        // reload with ignoreCache param
+        try ctx.processMessage(.{ .id = 32, .method = "Page.reload", .params = .{ .ignoreCache = true } });
+    }
+}

src/cdp/domains/security.zig

@@ -44,7 +44,7 @@ fn setIgnoreCertificateErrors(cmd: anytype) !void {
 const testing = @import("../testing.zig");
 
 test "cdp.Security: setIgnoreCertificateErrors" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     _ = try ctx.loadBrowserContext(.{ .id = "BID-9" });

src/cdp/domains/storage.zig

@@ -243,7 +243,7 @@ pub fn writeCookie(cookie: *const Cookie, w: anytype) !void {
 const testing = @import("../testing.zig");
 
 test "cdp.Storage: cookies" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     _ = try ctx.loadBrowserContext(.{ .id = "BID-S" });
 

src/cdp/domains/target.zig

@@ -512,7 +512,7 @@ const TargetInfo = struct {
 
 const testing = @import("../testing.zig");
 test "cdp.target: getBrowserContexts" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     // {
@@ -536,7 +536,7 @@ test "cdp.target: getBrowserContexts" {
 }
 
 test "cdp.target: createBrowserContext" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -554,7 +554,7 @@ test "cdp.target: createBrowserContext" {
 }
 
 test "cdp.target: disposeBrowserContext" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -585,7 +585,7 @@ test "cdp.target: disposeBrowserContext" {
 
 test "cdp.target: createTarget" {
     {
-        var ctx = testing.context();
+        var ctx = try testing.context();
         defer ctx.deinit();
         try ctx.processMessage(.{ .id = 10, .method = "Target.createTarget", .params = .{ .url = "about:blank" } });
 
@@ -595,7 +595,7 @@ test "cdp.target: createTarget" {
     }
 
     {
-        var ctx = testing.context();
+        var ctx = try testing.context();
         defer ctx.deinit();
         // active auto attach to get the Target.attachedToTarget event.
         try ctx.processMessage(.{ .id = 9, .method = "Target.setAutoAttach", .params = .{ .autoAttach = true, .waitForDebuggerOnStart = false } });
@@ -607,7 +607,7 @@ test "cdp.target: createTarget" {
         try ctx.expectSentEvent("Target.attachedToTarget", .{ .sessionId = bc.session_id.?, .targetInfo = .{ .url = "about:blank", .title = "", .attached = true, .type = "page", .canAccessOpener = false, .browserContextId = bc.id, .targetId = bc.target_id.? } }, .{});
     }
 
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     const bc = try ctx.loadBrowserContext(.{ .id = "BID-9" });
     {
@@ -624,7 +624,7 @@ test "cdp.target: createTarget" {
 }
 
 test "cdp.target: closeTarget" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -655,7 +655,7 @@ test "cdp.target: closeTarget" {
 }
 
 test "cdp.target: attachToTarget" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -686,7 +686,7 @@ test "cdp.target: attachToTarget" {
 }
 
 test "cdp.target: getTargetInfo" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
 
     {
@@ -737,7 +737,7 @@ test "cdp.target: getTargetInfo" {
 }
 
 test "cdp.target: issue#474: attach to just created target" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     const bc = try ctx.loadBrowserContext(.{ .id = "BID-9" });
     {
@@ -752,7 +752,7 @@ test "cdp.target: issue#474: attach to just created target" {
 }
 
 test "cdp.target: detachFromTarget" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     const bc = try ctx.loadBrowserContext(.{ .id = "BID-9" });
     {
@@ -775,19 +775,19 @@ test "cdp.target: detachFromTarget" {
 }
 
 test "cdp.target: detachFromTarget without session" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     _ = try ctx.loadBrowserContext(.{ .id = "BID-9" });
     {
         // detach when no session is attached should not send event
         try ctx.processMessage(.{ .id = 10, .method = "Target.detachFromTarget" });
         try ctx.expectSentResult(null, .{ .id = 10 });
-        try ctx.expectSentCount(0);
+        try ctx.expectSentCount(1);
     }
 }
 
 test "cdp.target: setAutoAttach false sends detachedFromTarget" {
-    var ctx = testing.context();
+    var ctx = try testing.context();
     defer ctx.deinit();
     const bc = try ctx.loadBrowserContext(.{ .id = "BID-9" });
     {

src/cdp/testing.zig

@@ -18,12 +18,14 @@
 
 const std = @import("std");
 const json = std.json;
+const posix = std.posix;
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
 
 const Testing = @This();
 
-const main = @import("cdp.zig");
+const CDP = @import("CDP.zig");
+const Server = @import("../Server.zig");
 
 const base = @import("../testing.zig");
 pub const allocator = base.allocator;
@@ -35,61 +37,27 @@ pub const expectEqualSlices = base.expectEqualSlices;
 pub const pageTest = base.pageTest;
 pub const newString = base.newString;
 
-const Client = struct {
-    allocator: Allocator,
-    send_arena: ArenaAllocator,
-    sent: std.ArrayList(json.Value) = .{},
-    serialized: std.ArrayList([]const u8) = .{},
-
-    fn init(alloc: Allocator) Client {
-        return .{
-            .allocator = alloc,
-            .send_arena = ArenaAllocator.init(alloc),
-        };
-    }
-
-    pub fn sendAllocator(self: *Client) Allocator {
-        return self.send_arena.allocator();
-    }
-
-    pub fn sendJSON(self: *Client, message: anytype, opts: json.Stringify.Options) !void {
-        var opts_copy = opts;
-        opts_copy.whitespace = .indent_2;
-        const serialized = try json.Stringify.valueAlloc(self.allocator, message, opts_copy);
-        try self.serialized.append(self.allocator, serialized);
-
-        const value = try json.parseFromSliceLeaky(json.Value, self.allocator, serialized, .{});
-        try self.sent.append(self.allocator, value);
-    }
-
-    pub fn sendJSONRaw(self: *Client, buf: std.ArrayList(u8)) !void {
-        const value = try json.parseFromSliceLeaky(json.Value, self.allocator, buf.items, .{});
-        try self.sent.append(self.allocator, value);
-    }
-};
-
-const TestCDP = main.CDPT(struct {
-    pub const Client = *Testing.Client;
-});
-
 const TestContext = struct {
-    client: ?Client = null,
-    cdp_: ?TestCDP = null,
-    arena: ArenaAllocator,
+    read_at: usize = 0,
+    read_buf: [1024 * 32]u8 = undefined,
+    cdp_: ?CDP = null,
+    client: Server.Client,
+    socket: posix.socket_t,
+    received: std.ArrayList(json.Value) = .empty,
+    received_raw: std.ArrayList([]const u8) = .empty,
 
     pub fn deinit(self: *TestContext) void {
         if (self.cdp_) |*c| {
             c.deinit();
         }
-        self.arena.deinit();
+        self.client.deinit();
+        posix.close(self.socket);
+        base.reset();
     }
 
-    pub fn cdp(self: *TestContext) *TestCDP {
+    pub fn cdp(self: *TestContext) *CDP {
         if (self.cdp_ == null) {
-            self.client = Client.init(self.arena.allocator());
-            // Don't use the arena here. We want to detect leaks in CDP.
-            // The arena is only for test-specific stuff
-            self.cdp_ = TestCDP.init(base.test_app, base.test_http, &self.client.?) catch unreachable;
+            self.cdp_ = CDP.init(&self.client) catch |err| @panic(@errorName(err));
         }
         return &self.cdp_.?;
     }
@@ -100,7 +68,7 @@ const TestContext = struct {
         session_id: ?[]const u8 = null,
         url: ?[:0]const u8 = null,
     };
-    pub fn loadBrowserContext(self: *TestContext, opts: BrowserContextOpts) !*main.BrowserContext(TestCDP) {
+    pub fn loadBrowserContext(self: *TestContext, opts: BrowserContextOpts) !*CDP.BrowserContext(CDP) {
         var c = self.cdp();
         if (c.browser_context) |bc| {
             _ = c.disposeBrowserContext(bc.id);
@@ -130,7 +98,7 @@ const TestContext = struct {
             }
             const page = try bc.session.createPage();
             const full_url = try std.fmt.allocPrintSentinel(
-                self.arena.allocator(),
+                base.arena_allocator,
                 "http://127.0.0.1:9582/src/browser/tests/{s}",
                 .{url},
                 0,
@@ -143,19 +111,20 @@ const TestContext = struct {
     }
 
     pub fn processMessage(self: *TestContext, msg: anytype) !void {
-        var json_message: []const u8 = undefined;
-        if (@typeInfo(@TypeOf(msg)) != .pointer) {
-            json_message = try std.json.Stringify.valueAlloc(self.arena.allocator(), msg, .{});
-        } else {
+        const json_message: []const u8 = blk: {
+            if (@typeInfo(@TypeOf(msg)) != .pointer) {
+                break :blk try std.json.Stringify.valueAlloc(base.arena_allocator, msg, .{});
+            }
             // assume this is a string we want to send as-is, if it isn't, we'll
             // get a compile error, so no big deal.
-            json_message = msg;
-        }
+            break :blk msg;
+        };
         return self.cdp().processMessage(json_message);
     }
 
     pub fn expectSentCount(self: *TestContext, expected: usize) !void {
-        try expectEqual(expected, self.client.?.sent.items.len);
+        try self.read();
+        try expectEqual(expected, self.received.items.len);
     }
 
     const ExpectResultOpts = struct {
@@ -203,37 +172,135 @@ const TestContext = struct {
         index: ?usize = null,
     };
     pub fn expectSent(self: *TestContext, expected: anytype, opts: SentOpts) !void {
-        const serialized = try json.Stringify.valueAlloc(self.arena.allocator(), expected, .{
+        const serialized = try json.Stringify.valueAlloc(base.arena_allocator, expected, .{
             .whitespace = .indent_2,
             .emit_null_optional_fields = false,
         });
-
-        for (self.client.?.sent.items, 0..) |sent, i| {
-            if (try compareExpectedToSent(serialized, sent) == false) {
-                continue;
-            }
-
-            if (opts.index) |expected_index| {
-                if (expected_index != i) {
-                    return error.ErrorAtWrongIndex;
+        for (0..5) |_| {
+            for (self.received.items, 0..) |received, i| {
+                if (try compareExpectedToSent(serialized, received) == false) {
+                    continue;
                 }
-            }
-            _ = self.client.?.sent.orderedRemove(i);
-            _ = self.client.?.serialized.orderedRemove(i);
-            return;
-        }
 
-        std.debug.print("Error not found. Expecting:\n{s}\n\nGot:\n", .{serialized});
-        for (self.client.?.serialized.items, 0..) |sent, i| {
-            std.debug.print("#{d}\n{s}\n\n", .{ i, sent });
+                if (opts.index) |expected_index| {
+                    if (expected_index != i) {
+                        std.debug.print("Expected message at index: {d}, was at index: {d}\n", .{ expected_index, i });
+                        self.dumpReceived();
+                        return error.ErrorAtWrongIndex;
+                    }
+                }
+                return;
+            }
+            std.Thread.sleep(5 * std.time.ns_per_ms);
+            try self.read();
         }
+        self.dumpReceived();
         return error.ErrorNotFound;
     }
+
+    fn dumpReceived(self: *const TestContext) void {
+        std.debug.print("CDP Message Received ({d})\n", .{self.received_raw.items.len});
+        for (self.received_raw.items, 0..) |received, i| {
+            std.debug.print("===Message: {d}===\n{s}\n\n", .{ i, received });
+        }
+    }
+
+    pub fn getSentMessage(self: *TestContext, index: usize) !?json.Value {
+        for (0..5) |_| {
+            if (index < self.received.items.len) {
+                return self.received.items[index];
+            }
+            std.Thread.sleep(5 * std.time.ns_per_ms);
+            try self.read();
+        }
+        return null;
+    }
+
+    fn read(self: *TestContext) !void {
+        while (true) {
+            const n = posix.read(self.socket, self.read_buf[self.read_at..]) catch |err| switch (err) {
+                error.WouldBlock => return,
+                else => return err,
+            };
+
+            if (n == 0) {
+                return;
+            }
+
+            self.read_at += n;
+
+            // Try to parse complete WebSocket frames
+            var pos: usize = 0;
+            while (pos < self.read_at) {
+                // Need at least 2 bytes for header
+                if (self.read_at - pos < 2) break;
+
+                const opcode = self.read_buf[pos] & 0x0F;
+                const payload_len_byte = self.read_buf[pos + 1] & 0x7F;
+
+                var header_size: usize = 2;
+                var payload_len: usize = payload_len_byte;
+
+                if (payload_len_byte == 126) {
+                    if (self.read_at - pos < 4) break;
+                    payload_len = std.mem.readInt(u16, self.read_buf[pos + 2 ..][0..2], .big);
+                    header_size = 4;
+                }
+                // Skip 8-byte length case (127) - not needed
+
+                const frame_size = header_size + payload_len;
+                if (self.read_at - pos < frame_size) break;
+
+                // We have a complete frame - process text (1) or binary (2), skip others
+                if (opcode == 1 or opcode == 2) {
+                    const payload = self.read_buf[pos + header_size ..][0..payload_len];
+                    const parsed = try std.json.parseFromSliceLeaky(json.Value, base.arena_allocator, payload, .{});
+                    try self.received.append(base.arena_allocator, parsed);
+                    try self.received_raw.append(base.arena_allocator, try base.arena_allocator.dupe(u8, payload));
+                }
+
+                pos += frame_size;
+            }
+
+            // Move remaining partial data to beginning of buffer
+            if (pos > 0 and pos < self.read_at) {
+                std.mem.copyForwards(u8, &self.read_buf, self.read_buf[pos..self.read_at]);
+                self.read_at -= pos;
+            } else if (pos == self.read_at) {
+                self.read_at = 0;
+            }
+        }
+    }
 };
 
-pub fn context() TestContext {
+pub fn context() !TestContext {
+    var pair: [2]posix.socket_t = undefined;
+    const rc = std.c.socketpair(posix.AF.LOCAL, posix.SOCK.STREAM, 0, &pair);
+    if (rc != 0) {
+        return error.SocketPairFailed;
+    }
+
+    errdefer {
+        posix.close(pair[0]);
+        posix.close(pair[1]);
+    }
+
+    const timeout = std.mem.toBytes(posix.timeval{ .sec = 0, .usec = 5_000 });
+    try posix.setsockopt(pair[0], posix.SOL.SOCKET, posix.SO.RCVTIMEO, &timeout);
+    try posix.setsockopt(pair[0], posix.SOL.SOCKET, posix.SO.SNDTIMEO, &timeout);
+    try posix.setsockopt(pair[1], posix.SOL.SOCKET, posix.SO.RCVTIMEO, &timeout);
+    try posix.setsockopt(pair[1], posix.SOL.SOCKET, posix.SO.SNDTIMEO, &timeout);
+
+    try posix.setsockopt(pair[0], posix.SOL.SOCKET, posix.SO.RCVBUF, &std.mem.toBytes(@as(c_int, 32_768)));
+    try posix.setsockopt(pair[0], posix.SOL.SOCKET, posix.SO.SNDBUF, &std.mem.toBytes(@as(c_int, 32_768)));
+    try posix.setsockopt(pair[1], posix.SOL.SOCKET, posix.SO.RCVBUF, &std.mem.toBytes(@as(c_int, 32_768)));
+    try posix.setsockopt(pair[1], posix.SOL.SOCKET, posix.SO.SNDBUF, &std.mem.toBytes(@as(c_int, 32_768)));
+
+    const client = try Server.Client.init(pair[1], base.arena_allocator, base.test_app, "json-version", 2000);
+
     return .{
-        .arena = ArenaAllocator.init(std.testing.allocator),
+        .client = client,
+        .socket = pair[0],
     };
 }
 

src/html5ever/lib.rs

@@ -158,13 +158,13 @@ pub extern "C" fn html5ever_attribute_iterator_next(
 
     let attr = &iter.vec[pos];
     iter.pos += 1;
-    return CNullable::<CAttribute>::some(CAttribute {
+    CNullable::<CAttribute>::some(CAttribute {
         name: CQualName::create(&attr.name),
         value: StringSlice {
             ptr: attr.value.as_ptr(),
             len: attr.value.len(),
         },
-    });
+    })
 }
 
 #[no_mangle]
@@ -186,12 +186,12 @@ pub extern "C" fn html5ever_get_memory_usage() -> Memory {
     use tikv_jemalloc_ctl::{epoch, stats};
 
     // many statistics are cached and only updated when the epoch is advanced.
-    epoch::advance().unwrap();
+    drop(epoch::advance());
 
-    return Memory {
-        resident: stats::resident::read().unwrap(),
-        allocated: stats::allocated::read().unwrap(),
-    };
+    Memory {
+        resident: stats::resident::read().unwrap_or(0),
+        allocated: stats::allocated::read().unwrap_or(0),
+    }
 }
 
 // Streaming parser API
@@ -325,7 +325,7 @@ pub extern "C" fn html5ever_streaming_parser_destroy(parser_ptr: *mut c_void) {
     // Drop the parser box without finishing
     // This is for cases where you want to cancel parsing
     unsafe {
-        let _ = Box::from_raw(parser_ptr as *mut StreamingParser);
+        drop(Box::from_raw(parser_ptr as *mut StreamingParser));
     }
 }
 

src/html5ever/sink.rs

@@ -36,10 +36,10 @@ pub struct ElementData {
 }
 impl ElementData {
     fn new(qname: QualName, flags: ElementFlags) -> Self {
-        return Self {
+        Self {
             qname: qname,
             mathml_annotation_xml_integration_point: flags.mathml_annotation_xml_integration_point,
-        };
+        }
     }
 }
 
@@ -130,12 +130,12 @@ impl<'arena> TreeSink for Sink<'arena> {
         unsafe {
             let mut attribute_iterator = CAttributeIterator { vec: attrs, pos: 0 };
 
-            return (self.create_element_callback)(
+            (self.create_element_callback)(
                 self.ctx,
                 data as *mut _ as *mut c_void,
                 CQualName::create(&name),
                 &mut attribute_iterator as *mut _ as *mut c_void,
-            );
+            )
         }
     }
 

src/html5ever/types.rs

@@ -126,21 +126,21 @@ impl CQualName {
             None => CNullable::<StringSlice>::none(),
             Some(prefix) => CNullable::<StringSlice>::some(StringSlice { ptr: prefix.as_ptr(), len: prefix.len()}),
         };
-        return CQualName{
+        CQualName{
             // inner: q as *const _ as *const c_void,
             ns: ns,
             local: local,
             prefix: prefix,
-        };
+        }
     }
 }
 impl Default for CQualName {
     fn default() -> Self {
-        return Self{
+        Self{
             prefix: CNullable::<StringSlice>::none(),
             ns: StringSlice::default(),
             local: StringSlice::default(),
-        };
+        }
     }
 }
 

src/lightpanda.zig

@@ -35,6 +35,7 @@ pub const markdown = @import("browser/markdown.zig");
 pub const SemanticTree = @import("SemanticTree.zig");
 pub const CDPNode = @import("cdp/Node.zig");
 pub const interactive = @import("browser/interactive.zig");
+pub const links = @import("browser/links.zig");
 pub const forms = @import("browser/forms.zig");
 pub const actions = @import("browser/actions.zig");
 pub const structured_data = @import("browser/structured_data.zig");

src/mcp/resources.zig

@@ -22,12 +22,14 @@ pub const resource_list = [_]protocol.Resource{
 };
 
 pub fn handleList(server: *Server, req: protocol.Request) !void {
-    try server.sendResult(req.id.?, .{ .resources = &resource_list });
+    const id = req.id orelse return;
+    try server.sendResult(id, .{ .resources = &resource_list });
 }
 
 const ReadParams = struct {
     uri: []const u8,
 };
+const Format = enum { html, markdown };
 
 const ResourceStreamingResult = struct {
     contents: []const struct {
@@ -38,7 +40,7 @@ const ResourceStreamingResult = struct {
 
     const StreamingText = struct {
         page: *lp.Page,
-        format: enum { html, markdown },
+        format: Format,
 
         pub fn jsonStringify(self: @This(), jw: *std.json.Stringify) !void {
             try jw.beginWriteRaw();
@@ -47,9 +49,11 @@ const ResourceStreamingResult = struct {
             switch (self.format) {
                 .html => lp.dump.root(self.page.document, .{}, &escaped.writer, self.page) catch |err| {
                     log.err(.mcp, "html dump failed", .{ .err = err });
+                    return error.WriteFailed;
                 },
                 .markdown => lp.markdown.dump(self.page.document.asNode(), .{}, &escaped.writer, self.page) catch |err| {
                     log.err(.mcp, "markdown dump failed", .{ .err = err });
+                    return error.WriteFailed;
                 },
             }
             try jw.writer.writeByte('"');
@@ -86,28 +90,25 @@ pub fn handleRead(server: *Server, arena: std.mem.Allocator, req: protocol.Reque
         return server.sendError(req_id, .PageNotLoaded, "Page not loaded");
     };
 
-    switch (uri) {
-        .@"mcp://page/html" => {
-            const result: ResourceStreamingResult = .{
-                .contents = &.{.{
-                    .uri = params.uri,
-                    .mimeType = "text/html",
-                    .text = .{ .page = page, .format = .html },
-                }},
-            };
-            try server.sendResult(req_id, result);
-        },
-        .@"mcp://page/markdown" => {
-            const result: ResourceStreamingResult = .{
-                .contents = &.{.{
-                    .uri = params.uri,
-                    .mimeType = "text/markdown",
-                    .text = .{ .page = page, .format = .markdown },
-                }},
-            };
-            try server.sendResult(req_id, result);
-        },
-    }
+    const format: Format = switch (uri) {
+        .@"mcp://page/html" => .html,
+        .@"mcp://page/markdown" => .markdown,
+    };
+    const mime_type: []const u8 = switch (uri) {
+        .@"mcp://page/html" => "text/html",
+        .@"mcp://page/markdown" => "text/markdown",
+    };
+
+    const result: ResourceStreamingResult = .{
+        .contents = &.{.{
+            .uri = params.uri,
+            .mimeType = mime_type,
+            .text = .{ .page = page, .format = format },
+        }},
+    };
+    server.sendResult(req_id, result) catch {
+        return server.sendError(req_id, .InternalError, "Failed to serialize resource content");
+    };
 }
 
 const testing = @import("../testing.zig");

src/mcp/router.zig

@@ -16,6 +16,7 @@ pub fn processRequests(server: *Server, reader: *std.io.Reader) !void {
         const buffered_line = reader.takeDelimiter('\n') catch |err| switch (err) {
             error.StreamTooLong => {
                 log.err(.mcp, "Message too long", .{});
+                try server.sendError(.null, .InvalidRequest, "Message too long");
                 continue;
             },
             else => return err,
@@ -80,6 +81,7 @@ pub fn handleMessage(server: *Server, arena: std.mem.Allocator, msg: []const u8)
 }
 
 fn handleInitialize(server: *Server, req: protocol.Request) !void {
+    const id = req.id orelse return;
     const result = protocol.InitializeResult{
         .protocolVersion = "2025-11-25",
         .capabilities = .{
@@ -92,7 +94,7 @@ fn handleInitialize(server: *Server, req: protocol.Request) !void {
         },
     };
 
-    try server.sendResult(req.id.?, result);
+    try server.sendResult(id, result);
 }
 
 fn handlePing(server: *Server, req: protocol.Request) !void {

src/mcp/tools.zig

@@ -172,13 +172,18 @@ pub const tool_list = [_]protocol.Tool{
 
 pub fn handleList(server: *Server, arena: std.mem.Allocator, req: protocol.Request) !void {
     _ = arena;
-    try server.sendResult(req.id.?, .{ .tools = &tool_list });
+    const id = req.id orelse return;
+    try server.sendResult(id, .{ .tools = &tool_list });
 }
 
 const GotoParams = struct {
     url: [:0]const u8,
 };
 
+const UrlParams = struct {
+    url: ?[:0]const u8 = null,
+};
+
 const EvaluateParams = struct {
     script: [:0]const u8,
     url: ?[:0]const u8 = null,
@@ -201,28 +206,18 @@ const ToolStreamingText = struct {
         switch (self.action) {
             .markdown => lp.markdown.dump(self.page.document.asNode(), .{}, w, self.page) catch |err| {
                 log.err(.mcp, "markdown dump failed", .{ .err = err });
+                return error.WriteFailed;
             },
             .links => {
-                if (Selector.querySelectorAll(self.page.document.asNode(), "a[href]", self.page)) |list| {
-                    defer list.deinit(self.page._session);
-
-                    var first = true;
-                    for (list._nodes) |node| {
-                        if (node.is(Element.Html.Anchor)) |anchor| {
-                            const href = anchor.getHref(self.page) catch |err| {
-                                log.err(.mcp, "resolve href failed", .{ .err = err });
-                                continue;
-                            };
-
-                            if (href.len > 0) {
-                                if (!first) try w.writeByte('\n');
-                                try w.writeAll(href);
-                                first = false;
-                            }
-                        }
-                    }
-                } else |err| {
+                const links = lp.links.collectLinks(self.page.call_arena, self.page.document.asNode(), self.page) catch |err| {
                     log.err(.mcp, "query links failed", .{ .err = err });
+                    return error.WriteFailed;
+                };
+                var first = true;
+                for (links) |href| {
+                    if (!first) try w.writeByte('\n');
+                    try w.writeAll(href);
+                    first = false;
                 }
             },
             .semantic_tree => {
@@ -248,6 +243,7 @@ const ToolStreamingText = struct {
 
                 st.textStringify(w) catch |err| {
                     log.err(.mcp, "semantic tree dump failed", .{ .err = err });
+                    return error.WriteFailed;
                 };
             },
         }
@@ -324,7 +320,7 @@ pub fn handleCall(server: *Server, arena: std.mem.Allocator, req: protocol.Reque
 }
 
 fn handleGoto(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const args = try parseArguments(GotoParams, arena, arguments, server, id, "goto");
+    const args = try parseArgs(GotoParams, arena, arguments, server, id, "goto");
     try performGoto(server, args.url, id);
 
     const content = [_]protocol.TextContent([]const u8){.{ .text = "Navigated successfully." }};
@@ -332,45 +328,27 @@ fn handleGoto(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arg
 }
 
 fn handleMarkdown(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const MarkdownParams = struct {
-        url: ?[:0]const u8 = null,
-    };
-    if (arguments) |args_raw| {
-        if (std.json.parseFromValueLeaky(MarkdownParams, arena, args_raw, .{ .ignore_unknown_fields = true })) |args| {
-            if (args.url) |u| {
-                try performGoto(server, u, id);
-            }
-        } else |_| {}
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const content = [_]protocol.TextContent(ToolStreamingText){.{
         .text = .{ .page = page, .action = .markdown },
     }};
-    try server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content });
+    server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content }) catch {
+        return server.sendError(id, .InternalError, "Failed to serialize markdown content");
+    };
 }
 
 fn handleLinks(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const LinksParams = struct {
-        url: ?[:0]const u8 = null,
-    };
-    if (arguments) |args_raw| {
-        if (std.json.parseFromValueLeaky(LinksParams, arena, args_raw, .{ .ignore_unknown_fields = true })) |args| {
-            if (args.url) |u| {
-                try performGoto(server, u, id);
-            }
-        } else |_| {}
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const content = [_]protocol.TextContent(ToolStreamingText){.{
         .text = .{ .page = page, .action = .links },
     }};
-    try server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content });
+    server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content }) catch {
+        return server.sendError(id, .InternalError, "Failed to serialize links content");
+    };
 }
 
 fn handleSemanticTree(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
@@ -379,44 +357,38 @@ fn handleSemanticTree(server: *Server, arena: std.mem.Allocator, id: std.json.Va
         backendNodeId: ?u32 = null,
         maxDepth: ?u32 = null,
     };
-    var tree_args: TreeParams = .{};
-    if (arguments) |args_raw| {
-        if (std.json.parseFromValueLeaky(TreeParams, arena, args_raw, .{ .ignore_unknown_fields = true })) |args| {
-            tree_args = args;
-            if (args.url) |u| {
-                try performGoto(server, u, id);
-            }
-        } else |_| {}
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(TreeParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const content = [_]protocol.TextContent(ToolStreamingText){.{
-        .text = .{ .page = page, .action = .semantic_tree, .registry = &server.node_registry, .arena = arena, .backendNodeId = tree_args.backendNodeId, .maxDepth = tree_args.maxDepth },
+        .text = .{
+            .page = page,
+            .action = .semantic_tree,
+            .registry = &server.node_registry,
+            .arena = arena,
+            .backendNodeId = args.backendNodeId,
+            .maxDepth = args.maxDepth,
+        },
     }};
-    try server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content });
+    server.sendResult(id, protocol.CallToolResult(ToolStreamingText){ .content = &content }) catch {
+        return server.sendError(id, .InternalError, "Failed to serialize semantic tree content");
+    };
 }
 
 fn handleInteractiveElements(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const Params = struct {
-        url: ?[:0]const u8 = null,
-    };
-    if (arguments) |args_raw| {
-        if (std.json.parseFromValueLeaky(Params, arena, args_raw, .{ .ignore_unknown_fields = true })) |args| {
-            if (args.url) |u| {
-                try performGoto(server, u, id);
-            }
-        } else |_| {}
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const elements = lp.interactive.collectInteractiveElements(page.document.asNode(), arena, page) catch |err| {
         log.err(.mcp, "elements collection failed", .{ .err = err });
         return server.sendError(id, .InternalError, "Failed to collect interactive elements");
     };
+
+    lp.interactive.registerNodes(elements, &server.node_registry) catch |err| {
+        log.err(.mcp, "node registration failed", .{ .err = err });
+        return server.sendError(id, .InternalError, "Failed to register element nodes");
+    };
+
     var aw: std.Io.Writer.Allocating = .init(arena);
     try std.json.Stringify.value(elements, .{}, &aw.writer);
 
@@ -425,19 +397,8 @@ fn handleInteractiveElements(server: *Server, arena: std.mem.Allocator, id: std.
 }
 
 fn handleStructuredData(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const Params = struct {
-        url: ?[:0]const u8 = null,
-    };
-    if (arguments) |args_raw| {
-        if (std.json.parseFromValueLeaky(Params, arena, args_raw, .{ .ignore_unknown_fields = true })) |args| {
-            if (args.url) |u| {
-                try performGoto(server, u, id);
-            }
-        } else |_| {}
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const data = lp.structured_data.collectStructuredData(page.document.asNode(), arena, page) catch |err| {
         log.err(.mcp, "struct data collection failed", .{ .err = err });
@@ -451,20 +412,8 @@ fn handleStructuredData(server: *Server, arena: std.mem.Allocator, id: std.json.
 }
 
 fn handleDetectForms(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const Params = struct {
-        url: ?[:0]const u8 = null,
-    };
-    if (arguments) |args_raw| {
-        const args = std.json.parseFromValueLeaky(Params, arena, args_raw, .{ .ignore_unknown_fields = true }) catch {
-            return server.sendError(id, .InvalidParams, "Invalid arguments for detectForms");
-        };
-        if (args.url) |u| {
-            try performGoto(server, u, id);
-        }
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgsOrDefault(UrlParams, arena, arguments, server, id);
+    const page = try ensurePage(server, id, args.url);
 
     const forms_data = lp.forms.collectForms(arena, page.document.asNode(), page) catch |err| {
         log.err(.mcp, "form collection failed", .{ .err = err });
@@ -484,14 +433,8 @@ fn handleDetectForms(server: *Server, arena: std.mem.Allocator, id: std.json.Val
 }
 
 fn handleEvaluate(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arguments: ?std.json.Value) !void {
-    const args = try parseArguments(EvaluateParams, arena, arguments, server, id, "evaluate");
-
-    if (args.url) |url| {
-        try performGoto(server, url, id);
-    }
-    const page = server.session.currentPage() orelse {
-        return server.sendError(id, .PageNotLoaded, "Page not loaded");
-    };
+    const args = try parseArgs(EvaluateParams, arena, arguments, server, id, "evaluate");
+    const page = try ensurePage(server, id, args.url);
 
     var ls: js.Local.Scope = undefined;
     page.js.localScope(&ls);
@@ -520,7 +463,7 @@ fn handleClick(server: *Server, arena: std.mem.Allocator, id: std.json.Value, ar
     const ClickParams = struct {
         backendNodeId: CDPNode.Id,
     };
-    const args = try parseArguments(ClickParams, arena, arguments, server, id, "click");
+    const args = try parseArgs(ClickParams, arena, arguments, server, id, "click");
 
     const page = server.session.currentPage() orelse {
         return server.sendError(id, .PageNotLoaded, "Page not loaded");
@@ -552,7 +495,7 @@ fn handleFill(server: *Server, arena: std.mem.Allocator, id: std.json.Value, arg
         backendNodeId: CDPNode.Id,
         text: []const u8,
     };
-    const args = try parseArguments(FillParams, arena, arguments, server, id, "fill");
+    const args = try parseArgs(FillParams, arena, arguments, server, id, "fill");
 
     const page = server.session.currentPage() orelse {
         return server.sendError(id, .PageNotLoaded, "Page not loaded");
@@ -586,7 +529,7 @@ fn handleScroll(server: *Server, arena: std.mem.Allocator, id: std.json.Value, a
         x: ?i32 = null,
         y: ?i32 = null,
     };
-    const args = try parseArguments(ScrollParams, arena, arguments, server, id, "scroll");
+    const args = try parseArgs(ScrollParams, arena, arguments, server, id, "scroll");
 
     const page = server.session.currentPage() orelse {
         return server.sendError(id, .PageNotLoaded, "Page not loaded");
@@ -623,7 +566,7 @@ fn handleWaitForSelector(server: *Server, arena: std.mem.Allocator, id: std.json
         selector: [:0]const u8,
         timeout: ?u32 = null,
     };
-    const args = try parseArguments(WaitParams, arena, arguments, server, id, "waitForSelector");
+    const args = try parseArgs(WaitParams, arena, arguments, server, id, "waitForSelector");
 
     _ = server.session.currentPage() orelse {
         return server.sendError(id, .PageNotLoaded, "Page not loaded");
@@ -647,12 +590,38 @@ fn handleWaitForSelector(server: *Server, arena: std.mem.Allocator, id: std.json
     return server.sendResult(id, protocol.CallToolResult([]const u8){ .content = &content });
 }
 
-fn parseArguments(comptime T: type, arena: std.mem.Allocator, arguments: ?std.json.Value, server: *Server, id: std.json.Value, tool_name: []const u8) !T {
-    if (arguments == null) {
+fn ensurePage(server: *Server, id: std.json.Value, url: ?[:0]const u8) !*lp.Page {
+    if (url) |u| {
+        try performGoto(server, u, id);
+    }
+    return server.session.currentPage() orelse {
+        try server.sendError(id, .PageNotLoaded, "Page not loaded");
+        return error.PageNotLoaded;
+    };
+}
+
+/// Parses JSON arguments into a given struct type `T`.
+/// If the arguments are missing, it returns a default-initialized `T` (e.g., `.{}`).
+/// If the arguments are present but invalid, it sends an MCP error response and returns `error.InvalidParams`.
+/// Use this for tools where all arguments are optional.
+fn parseArgsOrDefault(comptime T: type, arena: std.mem.Allocator, arguments: ?std.json.Value, server: *Server, id: std.json.Value) !T {
+    const args_raw = arguments orelse return .{};
+    return std.json.parseFromValueLeaky(T, arena, args_raw, .{ .ignore_unknown_fields = true }) catch {
+        try server.sendError(id, .InvalidParams, "Invalid arguments");
+        return error.InvalidParams;
+    };
+}
+
+/// Parses JSON arguments into a given struct type `T`.
+/// If the arguments are missing or invalid, it automatically sends an MCP error response to the client
+/// and returns an `error.InvalidParams`.
+/// Use this for tools that require strict validation or mandatory arguments.
+fn parseArgs(comptime T: type, arena: std.mem.Allocator, arguments: ?std.json.Value, server: *Server, id: std.json.Value, tool_name: []const u8) !T {
+    const args_raw = arguments orelse {
         try server.sendError(id, .InvalidParams, "Missing arguments");
         return error.InvalidParams;
-    }
-    return std.json.parseFromValueLeaky(T, arena, arguments.?, .{ .ignore_unknown_fields = true }) catch {
+    };
+    return std.json.parseFromValueLeaky(T, arena, args_raw, .{ .ignore_unknown_fields = true }) catch {
         const msg = std.fmt.allocPrint(arena, "Invalid arguments for {s}", .{tool_name}) catch "Invalid arguments";
         try server.sendError(id, .InvalidParams, msg);
         return error.InvalidParams;
@@ -664,7 +633,10 @@ fn performGoto(server: *Server, url: [:0]const u8, id: std.json.Value) !void {
     if (session.page != null) {
         session.removePage();
     }
-    const page = try session.createPage();
+    const page = session.createPage() catch {
+        try server.sendError(id, .InternalError, "Failed to create page");
+        return error.NavigationFailed;
+    };
     page.navigate(url, .{
         .reason = .address_bar,
         .kind = .{ .push = null },
@@ -673,8 +645,14 @@ fn performGoto(server: *Server, url: [:0]const u8, id: std.json.Value) !void {
         return error.NavigationFailed;
     };
 
-    var runner = try session.runner(.{});
-    try runner.wait(.{ .ms = 2000 });
+    var runner = session.runner(.{}) catch {
+        try server.sendError(id, .InternalError, "Failed to start page runner");
+        return error.NavigationFailed;
+    };
+    runner.wait(.{ .ms = 2000 }) catch {
+        try server.sendError(id, .InternalError, "Timeout waiting for page load");
+        return error.NavigationFailed;
+    };
 }
 
 const router = @import("router.zig");

src/network/websocket.zig

@@ -324,7 +324,9 @@ pub const WsConnection = struct {
     pub fn init(socket: posix.socket_t, allocator: Allocator, json_version_response: []const u8, timeout_ms: u32) !WsConnection {
         const socket_flags = try posix.fcntl(socket, posix.F.GETFL, 0);
         const nonblocking = @as(u32, @bitCast(posix.O{ .NONBLOCK = true }));
-        assert(socket_flags & nonblocking == nonblocking, "WsConnection.init blocking", .{});
+        if (builtin.is_test == false) {
+            assert(socket_flags & nonblocking == nonblocking, "WsConnection.init blocking", .{});
+        }
 
         var reader = try Reader(true).init(allocator);
         errdefer reader.deinit();

src/testing.zig

@@ -410,21 +410,46 @@ fn runWebApiTest(test_file: [:0]const u8) !void {
     page.js.localScope(&ls);
     defer ls.deinit();
 
-    var try_catch: js.TryCatch = undefined;
-    try_catch.init(&ls.local);
-    defer try_catch.deinit();
+    {
+        var try_catch: js.TryCatch = undefined;
+        try_catch.init(&ls.local);
+        defer try_catch.deinit();
+
+        try page.navigate(url, .{});
+    }
 
-    try page.navigate(url, .{});
     var runner = try test_session.runner(.{});
     try runner.wait(.{ .ms = 2000 });
 
-    test_browser.runMicrotasks();
+    var wait_ms: u32 = 2000;
+    var timer = try std.time.Timer.start();
+    while (true) {
+        var try_catch: js.TryCatch = undefined;
+        try_catch.init(&ls.local);
+        defer try_catch.deinit();
 
-    ls.local.eval("testing.assertOk()", "testing.assertOk()") catch |err| {
-        const caught = try_catch.caughtOrError(arena_allocator, err);
-        std.debug.print("{s}: test failure\nError: {f}\n", .{ test_file, caught });
-        return err;
-    };
+        const js_val = ls.local.exec("testing.assertOk()", "testing.assertOk()") catch |err| {
+            const caught = try_catch.caughtOrError(arena_allocator, err);
+            std.debug.print("{s}: test failure\nError: {f}\n", .{ test_file, caught });
+            return err;
+        };
+        if (js_val.isTrue()) {
+            return;
+        }
+        switch (try runner.tick(.{ .ms = 20 })) {
+            .done => return error.TestNeverSignaledCompletion,
+            .ok => |next_ms| {
+                const ms_elapsed = timer.lap() / 1_000_000;
+                if (ms_elapsed >= wait_ms) {
+                    return error.TestTimedOut;
+                }
+                wait_ms -= @intCast(ms_elapsed);
+                if (next_ms > 0) {
+                    std.Thread.sleep(std.time.ns_per_ms * next_ms);
+                }
+            },
+        }
+    }
 }
 
 // Used by a few CDP tests - wouldn't be sad to see this go.
@@ -445,10 +470,6 @@ pub fn pageTest(comptime test_file: []const u8) !*Page {
     return page;
 }
 
-test {
-    std.testing.refAllDecls(@This());
-}
-
 const log = @import("log.zig");
 const TestHTTPServer = @import("TestHTTPServer.zig");